[attrs] Extract the pure inference of function attributes into

a standalone pass.

There is no call graph or even interesting analysis for this part of
function attributes -- it is literally inferring attributes based on the
target library identification. As such, we can do it using a much
simpler module pass that just walks the declarations. This can also
happen much earlier in the pass pipeline which has benefits for any
number of other passes.

In the process, I've cleaned up one particular aspect of the logic which
was necessary in order to separate the two passes cleanly. It now counts
inferred attributes independently rather than just counting all the
inferred attributes as one, and the counts are more clearly explained.

The two test cases we had for this code path are both ... woefully
inadequate and copies of each other. I've kept the superset test and
updated it. We need more testing here, but I had to pick somewhere to
stop fixing everything broken I saw here.

Differential Revision: http://reviews.llvm.org/D15676

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256466 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/InitializePasses.h b/include/llvm/InitializePasses.h
index 21002a9e1a6c4e1097114757f78191edc4634d23..cb2b1394e92bc1afc7a6bd4f7b67bc63e1cf7edc 100644 (file)
--- a/include/llvm/InitializePasses.h
+++ b/include/llvm/InitializePasses.h
@@ -145,6 +145,7 @@ void initializeIVUsersPass(PassRegistry&);
 void initializeIfConverterPass(PassRegistry&);
 void initializeInductiveRangeCheckEliminationPass(PassRegistry&);
 void initializeIndVarSimplifyPass(PassRegistry&);
+void initializeInferFunctionAttrsLegacyPassPass(PassRegistry&);
 void initializeInlineCostAnalysisPass(PassRegistry&);
 void initializeInstructionCombiningPassPass(PassRegistry&);
 void initializeInstCountPass(PassRegistry&);

diff --git a/include/llvm/Transforms/IPO/InferFunctionAttrs.h b/include/llvm/Transforms/IPO/InferFunctionAttrs.h
new file mode 100644 (file)
index 0000000..80afc02
--- /dev/null
+++ b/include/llvm/Transforms/IPO/InferFunctionAttrs.h
@@ -0,0 +1,38 @@
+//===-- InferFunctionAttrs.h - Infer implicit function attributes ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Interfaces for passes which infer implicit function attributes from the
+/// name and signature of function declarations.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_IPO_INFERFUNCTIONATTRS_H
+#define LLVM_TRANSFORMS_IPO_INFERFUNCTIONATTRS_H
+
+#include "llvm/IR/Module.h"
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+/// A pass which infers function attributes from the names and signatures of
+/// function declarations in a module.
+class InferFunctionAttrsPass {
+public:
+  static StringRef name() { return "InferFunctionAttrsPass"; }
+  PreservedAnalyses run(Module &M, AnalysisManager<Module> *AM);
+};
+
+/// Create a legacy pass manager instance of a pass to infer function
+/// attributes.
+Pass *createInferFunctionAttrsLegacyPass();
+
+}
+
+#endif // LLVM_TRANSFORMS_IPO_INFERFUNCTIONATTRS_H

diff --git a/lib/Passes/PassBuilder.cpp b/lib/Passes/PassBuilder.cpp
index e8d5459f011d445d622969c81a7b3a2da7a5117a..8ba81f72a71715c590b62ebd69d871c478c4d09a 100644 (file)
--- a/lib/Passes/PassBuilder.cpp
+++ b/lib/Passes/PassBuilder.cpp
@@ -30,6 +30,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Transforms/IPO/ForceFunctionAttrs.h"
+#include "llvm/Transforms/IPO/InferFunctionAttrs.h"
 #include "llvm/Transforms/IPO/StripDeadPrototypes.h"
 #include "llvm/Transforms/InstCombine/InstCombine.h"
 #include "llvm/Transforms/Scalar/ADCE.h"

diff --git a/lib/Passes/PassRegistry.def b/lib/Passes/PassRegistry.def
index b7683f12393095ab82e283db9951e0682c7dad77..241a78927c77eb210840329d7822e3cafcb6ebf2 100644 (file)
--- a/lib/Passes/PassRegistry.def
+++ b/lib/Passes/PassRegistry.def
@@ -28,6 +28,7 @@ MODULE_ANALYSIS("targetlibinfo", TargetLibraryAnalysis())
 #define MODULE_PASS(NAME, CREATE_PASS)
 #endif
 MODULE_PASS("forceattrs", ForceFunctionAttrsPass())
+MODULE_PASS("inferattrs", InferFunctionAttrsPass())
 MODULE_PASS("invalidate<all>", InvalidateAllAnalysesPass())
 MODULE_PASS("no-op-module", NoOpModulePass())
 MODULE_PASS("print", PrintModulePass(dbgs()))

diff --git a/lib/Transforms/IPO/CMakeLists.txt b/lib/Transforms/IPO/CMakeLists.txt
index f03f2dc4a72ce3a69a598c96cc623675f660a1b8..351b88fe2aa0ba224a585b3c54461bc4623d2cc2 100644 (file)
--- a/lib/Transforms/IPO/CMakeLists.txt
+++ b/lib/Transforms/IPO/CMakeLists.txt
@@ -13,6 +13,7 @@ add_llvm_library(LLVMipo
   GlobalOpt.cpp
   IPConstantPropagation.cpp
   IPO.cpp
+  InferFunctionAttrs.cpp
   InlineAlways.cpp
   InlineSimple.cpp
   Inliner.cpp

diff --git a/lib/Transforms/IPO/FunctionAttrs.cpp b/lib/Transforms/IPO/FunctionAttrs.cpp
index b268eff25928098d909f6cb2759cf09a947d0f83..6dcfb3f83004742f42666dc50c14ea12d120edab 100644 (file)
--- a/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -50,7 +50,6 @@ STATISTIC(NumReadNoneArg, "Number of arguments marked readnone");
 STATISTIC(NumReadOnlyArg, "Number of arguments marked readonly");
 STATISTIC(NumNoAlias, "Number of function returns marked noalias");
 STATISTIC(NumNonNullReturn, "Number of function returns marked nonnull");
-STATISTIC(NumAnnotated, "Number of attributes added to library functions");
 STATISTIC(NumNoRecurse, "Number of functions marked as norecurse");
 
 namespace {
@@ -942,48 +941,6 @@ static bool addNonNullAttrs(const SCCNodeSet &SCCNodes,
   return MadeChange;
 }
 
-static void setDoesNotAccessMemory(Function &F) {
-  if (!F.doesNotAccessMemory()) {
-    F.setDoesNotAccessMemory();
-    ++NumAnnotated;
-  }
-}
-
-static void setOnlyReadsMemory(Function &F) {
-  if (!F.onlyReadsMemory()) {
-    F.setOnlyReadsMemory();
-    ++NumAnnotated;
-  }
-}
-
-static void setDoesNotThrow(Function &F) {
-  if (!F.doesNotThrow()) {
-    F.setDoesNotThrow();
-    ++NumAnnotated;
-  }
-}
-
-static void setDoesNotCapture(Function &F, unsigned n) {
-  if (!F.doesNotCapture(n)) {
-    F.setDoesNotCapture(n);
-    ++NumAnnotated;
-  }
-}
-
-static void setOnlyReadsMemory(Function &F, unsigned n) {
-  if (!F.onlyReadsMemory(n)) {
-    F.setOnlyReadsMemory(n);
-    ++NumAnnotated;
-  }
-}
-
-static void setDoesNotAlias(Function &F, unsigned n) {
-  if (!F.doesNotAlias(n)) {
-    F.setDoesNotAlias(n);
-    ++NumAnnotated;
-  }
-}
-
 static bool setDoesNotRecurse(Function &F) {
   if (F.doesNotRecurse())
     return false;
@@ -992,809 +949,6 @@ static bool setDoesNotRecurse(Function &F) {
   return true;
 }
 
-/// Analyze the name and prototype of the given function and set any applicable
-/// attributes.
-///
-/// Returns true if any attributes were set and false otherwise.
-static bool inferPrototypeAttributes(Function &F, const TargetLibraryInfo &TLI) {
-  if (F.hasFnAttribute(Attribute::OptimizeNone))
-    return false;
-
-  FunctionType *FTy = F.getFunctionType();
-  LibFunc::Func TheLibFunc;
-  if (!(TLI.getLibFunc(F.getName(), TheLibFunc) && TLI.has(TheLibFunc)))
-    return false;
-
-  switch (TheLibFunc) {
-  case LibFunc::strlen:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setOnlyReadsMemory(F);
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::strchr:
-  case LibFunc::strrchr:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isIntegerTy())
-      return false;
-    setOnlyReadsMemory(F);
-    setDoesNotThrow(F);
-    break;
-  case LibFunc::strtol:
-  case LibFunc::strtod:
-  case LibFunc::strtof:
-  case LibFunc::strtoul:
-  case LibFunc::strtoll:
-  case LibFunc::strtold:
-  case LibFunc::strtoull:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::strcpy:
-  case LibFunc::stpcpy:
-  case LibFunc::strcat:
-  case LibFunc::strncat:
-  case LibFunc::strncpy:
-  case LibFunc::stpncpy:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::strxfrm:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::strcmp: // 0,1
-  case LibFunc::strspn:  // 0,1
-  case LibFunc::strncmp: // 0,1
-  case LibFunc::strcspn: // 0,1
-  case LibFunc::strcoll: // 0,1
-  case LibFunc::strcasecmp:  // 0,1
-  case LibFunc::strncasecmp: //
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setOnlyReadsMemory(F);
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::strstr:
-  case LibFunc::strpbrk:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setOnlyReadsMemory(F);
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::strtok:
-  case LibFunc::strtok_r:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::scanf:
-    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::setbuf:
-  case LibFunc::setvbuf:
-    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::strdup:
-  case LibFunc::strndup:
-    if (FTy->getNumParams() < 1 || !FTy->getReturnType()->isPointerTy() ||
-        !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::stat:
-  case LibFunc::statvfs:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::sscanf:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::sprintf:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::snprintf:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(2)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 3);
-    setOnlyReadsMemory(F, 3);
-    break;
-  case LibFunc::setitimer:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy() ||
-        !FTy->getParamType(2)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    setDoesNotCapture(F, 3);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::system:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    // May throw; "system" is a valid pthread cancellation point.
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::malloc:
-    if (FTy->getNumParams() != 1 || !FTy->getReturnType()->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    break;
-  case LibFunc::memcmp:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setOnlyReadsMemory(F);
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::memchr:
-  case LibFunc::memrchr:
-    if (FTy->getNumParams() != 3)
-      return false;
-    setOnlyReadsMemory(F);
-    setDoesNotThrow(F);
-    break;
-  case LibFunc::modf:
-  case LibFunc::modff:
-  case LibFunc::modfl:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::memcpy:
-  case LibFunc::memccpy:
-  case LibFunc::memmove:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::memalign:
-    if (!FTy->getReturnType()->isPointerTy())
-      return false;
-    setDoesNotAlias(F, 0);
-    break;
-  case LibFunc::mkdir:
-    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::mktime:
-    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::realloc:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getReturnType()->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::read:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    // May throw; "read" is a valid pthread cancellation point.
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::rewind:
-    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::rmdir:
-  case LibFunc::remove:
-  case LibFunc::realpath:
-    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::rename:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::readlink:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::write:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    // May throw; "write" is a valid pthread cancellation point.
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::bcopy:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::bcmp:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setOnlyReadsMemory(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::bzero:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::calloc:
-    if (FTy->getNumParams() != 2 || !FTy->getReturnType()->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    break;
-  case LibFunc::chmod:
-  case LibFunc::chown:
-    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::ctermid:
-  case LibFunc::clearerr:
-  case LibFunc::closedir:
-    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::atoi:
-  case LibFunc::atol:
-  case LibFunc::atof:
-  case LibFunc::atoll:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setOnlyReadsMemory(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::access:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::fopen:
-    if (FTy->getNumParams() != 2 || !FTy->getReturnType()->isPointerTy() ||
-        !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::fdopen:
-    if (FTy->getNumParams() != 2 || !FTy->getReturnType()->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::feof:
-  case LibFunc::free:
-  case LibFunc::fseek:
-  case LibFunc::ftell:
-  case LibFunc::fgetc:
-  case LibFunc::fseeko:
-  case LibFunc::ftello:
-  case LibFunc::fileno:
-  case LibFunc::fflush:
-  case LibFunc::fclose:
-  case LibFunc::fsetpos:
-  case LibFunc::flockfile:
-  case LibFunc::funlockfile:
-  case LibFunc::ftrylockfile:
-    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::ferror:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F);
-    break;
-  case LibFunc::fputc:
-  case LibFunc::fstat:
-  case LibFunc::frexp:
-  case LibFunc::frexpf:
-  case LibFunc::frexpl:
-  case LibFunc::fstatvfs:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::fgets:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(2)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 3);
-    break;
-  case LibFunc::fread:
-    if (FTy->getNumParams() != 4 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(3)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 4);
-    break;
-  case LibFunc::fwrite:
-    if (FTy->getNumParams() != 4 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(3)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 4);
-    break;
-  case LibFunc::fputs:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::fscanf:
-  case LibFunc::fprintf:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::fgetpos:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::getc:
-  case LibFunc::getlogin_r:
-  case LibFunc::getc_unlocked:
-    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::getenv:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setOnlyReadsMemory(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::gets:
-  case LibFunc::getchar:
-    setDoesNotThrow(F);
-    break;
-  case LibFunc::getitimer:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::getpwnam:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::ungetc:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::uname:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::unlink:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::unsetenv:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::utime:
-  case LibFunc::utimes:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::putc:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::puts:
-  case LibFunc::printf:
-  case LibFunc::perror:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::pread:
-    if (FTy->getNumParams() != 4 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    // May throw; "pread" is a valid pthread cancellation point.
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::pwrite:
-    if (FTy->getNumParams() != 4 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    // May throw; "pwrite" is a valid pthread cancellation point.
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::putchar:
-    setDoesNotThrow(F);
-    break;
-  case LibFunc::popen:
-    if (FTy->getNumParams() != 2 || !FTy->getReturnType()->isPointerTy() ||
-        !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::pclose:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::vscanf:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::vsscanf:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy() ||
-        !FTy->getParamType(2)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::vfscanf:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy() ||
-        !FTy->getParamType(2)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::valloc:
-    if (!FTy->getReturnType()->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    break;
-  case LibFunc::vprintf:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::vfprintf:
-  case LibFunc::vsprintf:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::vsnprintf:
-    if (FTy->getNumParams() != 4 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(2)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 3);
-    setOnlyReadsMemory(F, 3);
-    break;
-  case LibFunc::open:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    // May throw; "open" is a valid pthread cancellation point.
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::opendir:
-    if (FTy->getNumParams() != 1 || !FTy->getReturnType()->isPointerTy() ||
-        !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::tmpfile:
-    if (!FTy->getReturnType()->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    break;
-  case LibFunc::times:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::htonl:
-  case LibFunc::htons:
-  case LibFunc::ntohl:
-  case LibFunc::ntohs:
-    setDoesNotThrow(F);
-    setDoesNotAccessMemory(F);
-    break;
-  case LibFunc::lstat:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::lchown:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::qsort:
-    if (FTy->getNumParams() != 4 || !FTy->getParamType(3)->isPointerTy())
-      return false;
-    // May throw; places call through function pointer.
-    setDoesNotCapture(F, 4);
-    break;
-  case LibFunc::dunder_strdup:
-  case LibFunc::dunder_strndup:
-    if (FTy->getNumParams() < 1 || !FTy->getReturnType()->isPointerTy() ||
-        !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::dunder_strtok_r:
-    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::under_IO_getc:
-    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::under_IO_putc:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::dunder_isoc99_scanf:
-    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::stat64:
-  case LibFunc::lstat64:
-  case LibFunc::statvfs64:
-    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::dunder_isoc99_sscanf:
-    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::fopen64:
-    if (FTy->getNumParams() != 2 || !FTy->getReturnType()->isPointerTy() ||
-        !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    setOnlyReadsMemory(F, 1);
-    setOnlyReadsMemory(F, 2);
-    break;
-  case LibFunc::fseeko64:
-  case LibFunc::ftello64:
-    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    break;
-  case LibFunc::tmpfile64:
-    if (!FTy->getReturnType()->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotAlias(F, 0);
-    break;
-  case LibFunc::fstat64:
-  case LibFunc::fstatvfs64:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
-      return false;
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 2);
-    break;
-  case LibFunc::open64:
-    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy())
-      return false;
-    // May throw; "open" is a valid pthread cancellation point.
-    setDoesNotCapture(F, 1);
-    setOnlyReadsMemory(F, 1);
-    break;
-  case LibFunc::gettimeofday:
-    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
-        !FTy->getParamType(1)->isPointerTy())
-      return false;
-    // Currently some platforms have the restrict keyword on the arguments to
-    // gettimeofday. To be conservative, do not add noalias to gettimeofday's
-    // arguments.
-    setDoesNotThrow(F);
-    setDoesNotCapture(F, 1);
-    setDoesNotCapture(F, 2);
-    break;
-  default:
-    // Didn't mark any attributes.
-    return false;
-  }
-
-  return true;
-}
-
 static bool addNoRecurseAttrs(const CallGraphSCC &SCC,
                               SmallVectorImpl<WeakVH> &Revisit) {
   // Try and identify functions that do not recurse.
@@ -1874,18 +1028,13 @@ bool FunctionAttrs::runOnSCC(CallGraphSCC &SCC) {
       continue;
     }
 
-    // When initially processing functions, also infer their prototype
-    // attributes if they are declarations.
-    if (F->isDeclaration())
-      Changed |= inferPrototypeAttributes(*F, *TLI);
-
     SCCNodes.insert(F);
   }
 
   Changed |= addReadAttrs(SCCNodes, AARGetter);
   Changed |= addArgumentAttrs(SCCNodes);
 
-  // If we have no external nodes participating in the SCC, we can infer some
+  // If we have no external nodes participating in the SCC, we can deduce some
   // more precise attributes as well.
   if (!ExternalNode) {
     Changed |= addNoAliasAttrs(SCCNodes);

diff --git a/lib/Transforms/IPO/IPO.cpp b/lib/Transforms/IPO/IPO.cpp
index 54f8de30e28abd9ecb3d076b25030f19fd729fdf..7ea6c08b2e6606cce2478d8458a86f1c8fc84351 100644 (file)
--- a/lib/Transforms/IPO/IPO.cpp
+++ b/lib/Transforms/IPO/IPO.cpp
@@ -34,6 +34,7 @@ void llvm::initializeIPO(PassRegistry &Registry) {
   initializeIPCPPass(Registry);
   initializeAlwaysInlinerPass(Registry);
   initializeSimpleInlinerPass(Registry);
+  initializeInferFunctionAttrsLegacyPassPass(Registry);
   initializeInternalizePassPass(Registry);
   initializeLoopExtractorPass(Registry);
   initializeBlockExtractorPassPass(Registry);

diff --git a/lib/Transforms/IPO/InferFunctionAttrs.cpp b/lib/Transforms/IPO/InferFunctionAttrs.cpp
new file mode 100644 (file)
index 0000000..d02c861
--- /dev/null
+++ b/lib/Transforms/IPO/InferFunctionAttrs.cpp
@@ -0,0 +1,937 @@
+//===- InferFunctionAttrs.cpp - Infer implicit function attributes --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/IPO/InferFunctionAttrs.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "inferattrs"
+
+STATISTIC(NumReadNone, "Number of functions inferred as readnone");
+STATISTIC(NumReadOnly, "Number of functions inferred as readonly");
+STATISTIC(NumNoUnwind, "Number of functions inferred as nounwind");
+STATISTIC(NumNoCapture, "Number of arguments inferred as nocapture");
+STATISTIC(NumReadOnlyArg, "Number of arguments inferred as readonly");
+STATISTIC(NumNoAlias, "Number of function returns inferred as noalias");
+
+static bool setDoesNotAccessMemory(Function &F) {
+  if (F.doesNotAccessMemory())
+    return false;
+  F.setDoesNotAccessMemory();
+  ++NumReadNone;
+  return true;
+}
+
+static bool setOnlyReadsMemory(Function &F) {
+  if (F.onlyReadsMemory())
+    return false;
+  F.setOnlyReadsMemory();
+  ++NumReadOnly;
+  return true;
+}
+
+static bool setDoesNotThrow(Function &F) {
+  if (F.doesNotThrow())
+    return false;
+  F.setDoesNotThrow();
+  ++NumNoUnwind;
+  return true;
+}
+
+static bool setDoesNotCapture(Function &F, unsigned n) {
+  if (F.doesNotCapture(n))
+    return false;
+  F.setDoesNotCapture(n);
+  ++NumNoCapture;
+  return true;
+}
+
+static bool setOnlyReadsMemory(Function &F, unsigned n) {
+  if (F.onlyReadsMemory(n))
+    return false;
+  F.setOnlyReadsMemory(n);
+  ++NumReadOnlyArg;
+  return true;
+}
+
+static bool setDoesNotAlias(Function &F, unsigned n) {
+  if (F.doesNotAlias(n))
+    return false;
+  F.setDoesNotAlias(n);
+  ++NumNoAlias;
+  return true;
+}
+
+/// Analyze the name and prototype of the given function and set any applicable
+/// attributes.
+///
+/// Returns true if any attributes were set and false otherwise.
+static bool inferPrototypeAttributes(Function &F,
+                                     const TargetLibraryInfo &TLI) {
+  if (F.hasFnAttribute(Attribute::OptimizeNone))
+    return false;
+
+  FunctionType *FTy = F.getFunctionType();
+  LibFunc::Func TheLibFunc;
+  if (!(TLI.getLibFunc(F.getName(), TheLibFunc) && TLI.has(TheLibFunc)))
+    return false;
+
+  bool Changed = false;
+
+  switch (TheLibFunc) {
+  case LibFunc::strlen:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setOnlyReadsMemory(F);
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::strchr:
+  case LibFunc::strrchr:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isIntegerTy())
+      return false;
+    Changed |= setOnlyReadsMemory(F);
+    Changed |= setDoesNotThrow(F);
+    return Changed;
+  case LibFunc::strtol:
+  case LibFunc::strtod:
+  case LibFunc::strtof:
+  case LibFunc::strtoul:
+  case LibFunc::strtoll:
+  case LibFunc::strtold:
+  case LibFunc::strtoull:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::strcpy:
+  case LibFunc::stpcpy:
+  case LibFunc::strcat:
+  case LibFunc::strncat:
+  case LibFunc::strncpy:
+  case LibFunc::stpncpy:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::strxfrm:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::strcmp:      // 0,1
+  case LibFunc::strspn:      // 0,1
+  case LibFunc::strncmp:     // 0,1
+  case LibFunc::strcspn:     // 0,1
+  case LibFunc::strcoll:     // 0,1
+  case LibFunc::strcasecmp:  // 0,1
+  case LibFunc::strncasecmp: //
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setOnlyReadsMemory(F);
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::strstr:
+  case LibFunc::strpbrk:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setOnlyReadsMemory(F);
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::strtok:
+  case LibFunc::strtok_r:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::scanf:
+    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::setbuf:
+  case LibFunc::setvbuf:
+    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::strdup:
+  case LibFunc::strndup:
+    if (FTy->getNumParams() < 1 || !FTy->getReturnType()->isPointerTy() ||
+        !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::stat:
+  case LibFunc::statvfs:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::sscanf:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::sprintf:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::snprintf:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(2)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 3);
+    Changed |= setOnlyReadsMemory(F, 3);
+    return Changed;
+  case LibFunc::setitimer:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy() ||
+        !FTy->getParamType(2)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setDoesNotCapture(F, 3);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::system:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    // May throw; "system" is a valid pthread cancellation point.
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::malloc:
+    if (FTy->getNumParams() != 1 || !FTy->getReturnType()->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    return Changed;
+  case LibFunc::memcmp:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setOnlyReadsMemory(F);
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::memchr:
+  case LibFunc::memrchr:
+    if (FTy->getNumParams() != 3)
+      return false;
+    Changed |= setOnlyReadsMemory(F);
+    Changed |= setDoesNotThrow(F);
+    return Changed;
+  case LibFunc::modf:
+  case LibFunc::modff:
+  case LibFunc::modfl:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::memcpy:
+  case LibFunc::memccpy:
+  case LibFunc::memmove:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::memalign:
+    if (!FTy->getReturnType()->isPointerTy())
+      return false;
+    Changed |= setDoesNotAlias(F, 0);
+    return Changed;
+  case LibFunc::mkdir:
+    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::mktime:
+    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::realloc:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getReturnType()->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::read:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    // May throw; "read" is a valid pthread cancellation point.
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::rewind:
+    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::rmdir:
+  case LibFunc::remove:
+  case LibFunc::realpath:
+    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::rename:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::readlink:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::write:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    // May throw; "write" is a valid pthread cancellation point.
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::bcopy:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::bcmp:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setOnlyReadsMemory(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::bzero:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::calloc:
+    if (FTy->getNumParams() != 2 || !FTy->getReturnType()->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    return Changed;
+  case LibFunc::chmod:
+  case LibFunc::chown:
+    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::ctermid:
+  case LibFunc::clearerr:
+  case LibFunc::closedir:
+    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::atoi:
+  case LibFunc::atol:
+  case LibFunc::atof:
+  case LibFunc::atoll:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setOnlyReadsMemory(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::access:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::fopen:
+    if (FTy->getNumParams() != 2 || !FTy->getReturnType()->isPointerTy() ||
+        !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::fdopen:
+    if (FTy->getNumParams() != 2 || !FTy->getReturnType()->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::feof:
+  case LibFunc::free:
+  case LibFunc::fseek:
+  case LibFunc::ftell:
+  case LibFunc::fgetc:
+  case LibFunc::fseeko:
+  case LibFunc::ftello:
+  case LibFunc::fileno:
+  case LibFunc::fflush:
+  case LibFunc::fclose:
+  case LibFunc::fsetpos:
+  case LibFunc::flockfile:
+  case LibFunc::funlockfile:
+  case LibFunc::ftrylockfile:
+    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::ferror:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F);
+    return Changed;
+  case LibFunc::fputc:
+  case LibFunc::fstat:
+  case LibFunc::frexp:
+  case LibFunc::frexpf:
+  case LibFunc::frexpl:
+  case LibFunc::fstatvfs:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::fgets:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(2)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 3);
+    return Changed;
+  case LibFunc::fread:
+    if (FTy->getNumParams() != 4 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(3)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 4);
+    return Changed;
+  case LibFunc::fwrite:
+    if (FTy->getNumParams() != 4 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(3)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 4);
+    return Changed;
+  case LibFunc::fputs:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::fscanf:
+  case LibFunc::fprintf:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::fgetpos:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::getc:
+  case LibFunc::getlogin_r:
+  case LibFunc::getc_unlocked:
+    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::getenv:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setOnlyReadsMemory(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::gets:
+  case LibFunc::getchar:
+    Changed |= setDoesNotThrow(F);
+    return Changed;
+  case LibFunc::getitimer:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::getpwnam:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::ungetc:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::uname:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::unlink:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::unsetenv:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::utime:
+  case LibFunc::utimes:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::putc:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::puts:
+  case LibFunc::printf:
+  case LibFunc::perror:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::pread:
+    if (FTy->getNumParams() != 4 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    // May throw; "pread" is a valid pthread cancellation point.
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::pwrite:
+    if (FTy->getNumParams() != 4 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    // May throw; "pwrite" is a valid pthread cancellation point.
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::putchar:
+    Changed |= setDoesNotThrow(F);
+    return Changed;
+  case LibFunc::popen:
+    if (FTy->getNumParams() != 2 || !FTy->getReturnType()->isPointerTy() ||
+        !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::pclose:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::vscanf:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::vsscanf:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy() ||
+        !FTy->getParamType(2)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::vfscanf:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy() ||
+        !FTy->getParamType(2)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::valloc:
+    if (!FTy->getReturnType()->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    return Changed;
+  case LibFunc::vprintf:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::vfprintf:
+  case LibFunc::vsprintf:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::vsnprintf:
+    if (FTy->getNumParams() != 4 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(2)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 3);
+    Changed |= setOnlyReadsMemory(F, 3);
+    return Changed;
+  case LibFunc::open:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    // May throw; "open" is a valid pthread cancellation point.
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::opendir:
+    if (FTy->getNumParams() != 1 || !FTy->getReturnType()->isPointerTy() ||
+        !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::tmpfile:
+    if (!FTy->getReturnType()->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    return Changed;
+  case LibFunc::times:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::htonl:
+  case LibFunc::htons:
+  case LibFunc::ntohl:
+  case LibFunc::ntohs:
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAccessMemory(F);
+    return Changed;
+  case LibFunc::lstat:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::lchown:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::qsort:
+    if (FTy->getNumParams() != 4 || !FTy->getParamType(3)->isPointerTy())
+      return false;
+    // May throw; places call through function pointer.
+    Changed |= setDoesNotCapture(F, 4);
+    return Changed;
+  case LibFunc::dunder_strdup:
+  case LibFunc::dunder_strndup:
+    if (FTy->getNumParams() < 1 || !FTy->getReturnType()->isPointerTy() ||
+        !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::dunder_strtok_r:
+    if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::under_IO_getc:
+    if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::under_IO_putc:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::dunder_isoc99_scanf:
+    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::stat64:
+  case LibFunc::lstat64:
+  case LibFunc::statvfs64:
+    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::dunder_isoc99_sscanf:
+    if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::fopen64:
+    if (FTy->getNumParams() != 2 || !FTy->getReturnType()->isPointerTy() ||
+        !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    Changed |= setOnlyReadsMemory(F, 1);
+    Changed |= setOnlyReadsMemory(F, 2);
+    return Changed;
+  case LibFunc::fseeko64:
+  case LibFunc::ftello64:
+    if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc::tmpfile64:
+    if (!FTy->getReturnType()->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 0);
+    return Changed;
+  case LibFunc::fstat64:
+  case LibFunc::fstatvfs64:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
+      return false;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+  case LibFunc::open64:
+    if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy())
+      return false;
+    // May throw; "open" is a valid pthread cancellation point.
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
+  case LibFunc::gettimeofday:
+    if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy() ||
+        !FTy->getParamType(1)->isPointerTy())
+      return false;
+    // Currently some platforms have the restrict keyword on the arguments to
+    // gettimeofday. To be conservative, do not add noalias to gettimeofday's
+    // arguments.
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setDoesNotCapture(F, 2);
+    return Changed;
+
+  default:
+    // FIXME: It'd be really nice to cover all the library functions we're
+    // aware of here.
+    return false;
+  }
+}
+
+static bool inferAllPrototypeAttributes(Module &M,
+                                        const TargetLibraryInfo &TLI) {
+  bool Changed = false;
+
+  for (Function &F : M.functions())
+    // We only infer things using the prototype if the definition isn't around
+    // to analyze directly.
+    if (F.isDeclaration())
+      Changed |= inferPrototypeAttributes(F, TLI);
+
+  return Changed;
+}
+
+PreservedAnalyses InferFunctionAttrsPass::run(Module &M,
+                                              AnalysisManager<Module> *AM) {
+  auto &TLI = AM->getResult<TargetLibraryAnalysis>(M);
+
+  if (!inferAllPrototypeAttributes(M, TLI))
+    // If we didn't infer anything, preserve all analyses.
+    return PreservedAnalyses::all();
+
+  // Otherwise, we may have changed fundamental function attributes, so clear
+  // out all the passes.
+  return PreservedAnalyses::none();
+}
+
+namespace {
+struct InferFunctionAttrsLegacyPass : public ModulePass {
+  static char ID; // Pass identification, replacement for typeid
+  InferFunctionAttrsLegacyPass() : ModulePass(ID) {
+    initializeInferFunctionAttrsLegacyPassPass(
+        *PassRegistry::getPassRegistry());
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addRequired<TargetLibraryInfoWrapperPass>();
+  }
+
+  bool runOnModule(Module &M) override {
+    auto &TLI = getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
+    return inferAllPrototypeAttributes(M, TLI);
+  }
+};
+}
+
+char InferFunctionAttrsLegacyPass::ID = 0;
+INITIALIZE_PASS_BEGIN(InferFunctionAttrsLegacyPass, "inferattrs",
+                      "Infer set function attributes", false, false)
+INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
+INITIALIZE_PASS_END(InferFunctionAttrsLegacyPass, "inferattrs",
+                    "Infer set function attributes", false, false)
+
+Pass *llvm::createInferFunctionAttrsLegacyPass() {
+  return new InferFunctionAttrsLegacyPass();
+}

diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
index 5978b8f59caf88fdaf580a364439cd7e7f2641be..9876efa7b235510423006a9834b0bf2d2767b917 100644 (file)
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -12,26 +12,26 @@
 //
 //===----------------------------------------------------------------------===//
 
-
 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 #include "llvm-c/Transforms/PassManagerBuilder.h"
 #include "llvm/ADT/SmallVector.h"
-#include "llvm/Analysis/Passes.h"
-#include "llvm/IR/DataLayout.h"
-#include "llvm/IR/FunctionInfo.h"
-#include "llvm/IR/Verifier.h"
-#include "llvm/IR/LegacyPassManager.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/ManagedStatic.h"
 #include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/CFLAliasAnalysis.h"
 #include "llvm/Analysis/GlobalsModRef.h"
+#include "llvm/Analysis/Passes.h"
 #include "llvm/Analysis/ScopedNoAliasAA.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TypeBasedAliasAnalysis.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/FunctionInfo.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ManagedStatic.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/IPO/ForceFunctionAttrs.h"
+#include "llvm/Transforms/IPO/InferFunctionAttrs.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Vectorize.h"
 
@@ -220,6 +220,9 @@ void PassManagerBuilder::populateModulePassManager(
   addInitialAliasAnalysisPasses(MPM);
 
   if (!DisableUnitAtATime) {
+    // Infer attributes about declarations if possible.
+    MPM.add(createInferFunctionAttrsLegacyPass());
+
     addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
 
     MPM.add(createIPSCCPPass());              // IP SCCP
@@ -490,6 +493,9 @@ void PassManagerBuilder::addLTOOptimizationPasses(legacy::PassManagerBase &PM) {
   // Allow forcing function attributes as a debugging and tuning aid.
   PM.add(createForceFunctionAttrsLegacyPass());
 
+  // Infer attributes about declarations if possible.
+  PM.add(createInferFunctionAttrsLegacyPass());
+
   // Propagate constants at call sites into the functions they call.  This
   // opens opportunities for globalopt (and inlining) by substituting function
   // pointers passed as arguments to direct uses of functions.

diff --git a/test/Transforms/FunctionAttrs/2009-01-04-Annotate.ll b/test/Transforms/FunctionAttrs/2009-01-04-Annotate.ll
deleted file mode 100644 (file)
index fa06cc7..0000000
--- a/test/Transforms/FunctionAttrs/2009-01-04-Annotate.ll
+++ /dev/null
@@ -1,21 +0,0 @@
-; RUN: opt < %s -functionattrs -S | FileCheck %s
-
-; CHECK: declare noalias i8* @fopen(i8* nocapture readonly, i8* nocapture readonly) #0
-declare i8* @fopen(i8*, i8*)
-
-; CHECK: declare i8 @strlen(i8* nocapture) #1
-declare i8 @strlen(i8*)
-
-; CHECK: declare noalias i32* @realloc(i32* nocapture, i32) #0
-declare i32* @realloc(i32*, i32)
-
-; Test deliberately wrong declaration
-declare i32 @strcpy(...)
-
-; CHECK-NOT: strcpy{{.*}}noalias
-; CHECK-NOT: strcpy{{.*}}nocapture
-; CHECK-NOT: strcpy{{.*}}nounwind
-; CHECK-NOT: strcpy{{.*}}readonly
-
-; CHECK: attributes #0 = { nounwind }
-; CHECK: attributes #1 = { nounwind readonly }

diff --git a/test/Transforms/FunctionAttrs/annotate-1.ll b/test/Transforms/FunctionAttrs/annotate-1.ll
deleted file mode 100644 (file)
index 9fba7a9..0000000
--- a/test/Transforms/FunctionAttrs/annotate-1.ll
+++ /dev/null
@@ -1,23 +0,0 @@
-; RUN: opt < %s -functionattrs -S | FileCheck %s
-; RUN: opt < %s -mtriple=x86_64-apple-macosx10.8.0 -functionattrs -S | FileCheck -check-prefix=CHECK-POSIX %s
-
-declare i8* @fopen(i8*, i8*)
-; CHECK: declare noalias i8* @fopen(i8* nocapture readonly, i8* nocapture readonly) [[G0:#[0-9]]] 
-
-declare i8 @strlen(i8*)
-; CHECK: declare i8 @strlen(i8* nocapture) [[G1:#[0-9]]]
-
-declare i32* @realloc(i32*, i32)
-; CHECK: declare noalias i32* @realloc(i32* nocapture, i32) [[G0]]
-
-; Test deliberately wrong declaration
-
-declare i32 @strcpy(...)
-; CHECK: declare i32 @strcpy(...)
-
-declare i32 @gettimeofday(i8*, i8*)
-; CHECK-POSIX: declare i32 @gettimeofday(i8* nocapture, i8* nocapture) [[G0:#[0-9]+]]
-
-; CHECK: attributes [[G0]] = { nounwind }
-; CHECK: attributes [[G1]] = { nounwind readonly }
-; CHECK-POSIX: attributes [[G0]] = { nounwind }

diff --git a/test/Transforms/InferFunctionAttrs/annotate.ll b/test/Transforms/InferFunctionAttrs/annotate.ll
new file mode 100644 (file)
index 0000000..963f484
--- /dev/null
+++ b/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -0,0 +1,24 @@
+; RUN: opt < %s -inferattrs -S | FileCheck %s
+; RUN: opt < %s -passes=inferattrs -S | FileCheck %s
+; RUN: opt < %s -mtriple=x86_64-apple-macosx10.8.0 -inferattrs -S | FileCheck -check-prefix=CHECK-POSIX %s
+
+declare i8* @fopen(i8*, i8*)
+; CHECK: declare noalias i8* @fopen(i8* nocapture readonly, i8* nocapture readonly) [[G0:#[0-9]]] 
+
+declare i8 @strlen(i8*)
+; CHECK: declare i8 @strlen(i8* nocapture) [[G1:#[0-9]]]
+
+declare i32* @realloc(i32*, i32)
+; CHECK: declare noalias i32* @realloc(i32* nocapture, i32) [[G0]]
+
+; Test deliberately wrong declaration
+
+declare i32 @strcpy(...)
+; CHECK: declare i32 @strcpy(...)
+
+declare i32 @gettimeofday(i8*, i8*)
+; CHECK-POSIX: declare i32 @gettimeofday(i8* nocapture, i8* nocapture) [[G0:#[0-9]+]]
+
+; CHECK: attributes [[G0]] = { nounwind }
+; CHECK: attributes [[G1]] = { nounwind readonly }
+; CHECK-POSIX: attributes [[G0]] = { nounwind }

diff --git a/test/Transforms/InstCombine/strto-1.ll b/test/Transforms/InstCombine/strto-1.ll
index fc35dddcae5a5337541d7ef6d6392c52996b41a9..96f36e8d89c7d5c7983425ba748ea2a15394aafd 100644 (file)
--- a/test/Transforms/InstCombine/strto-1.ll
+++ b/test/Transforms/InstCombine/strto-1.ll
@@ -1,6 +1,6 @@
 ; Test that the strto* library call simplifiers works correctly.
 ;
-; RUN: opt < %s -instcombine -functionattrs -S | FileCheck %s
+; RUN: opt < %s -instcombine -inferattrs -S | FileCheck %s
 
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"