From: Owen Anderson <resistor@mac.com>
Date: Sat, 1 May 2010 08:34:28 +0000 (+0000)
Subject: Disable the call-deletion transformation introduced in r86975.  Without
X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=commitdiff_plain;h=1b4a38646f6bbeb32a125a1f2316a7b2d27916d7

Disable the call-deletion transformation introduced in r86975.  Without
halting analysis, it is illegal to delete a call to a read-only function.
The correct solution is almost certainly to add a "must halt" attribute and
only allow deletions in its presence.

XFAIL the relevant testcase for now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102831 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/IPO/Inliner.cpp b/lib/Transforms/IPO/Inliner.cpp
index b785bb0a939..875c4fd7038 100644
--- a/lib/Transforms/IPO/Inliner.cpp
+++ b/lib/Transforms/IPO/Inliner.cpp
@@ -33,7 +33,8 @@
 using namespace llvm;
 
 STATISTIC(NumInlined, "Number of functions inlined");
-STATISTIC(NumCallsDeleted, "Number of call sites deleted, not inlined");
+// FIXME: Uncomment once call deletion xform is made safe
+// STATISTIC(NumCallsDeleted, "Number of call sites deleted, not inlined");
 STATISTIC(NumDeleted, "Number of functions deleted because all callers found");
 STATISTIC(NumMergedAllocas, "Number of allocas merged together");
 
@@ -382,6 +383,9 @@ bool Inliner::runOnSCC(CallGraphSCC &SCC) {
       Function *Caller = CS.getCaller();
       Function *Callee = CS.getCalledFunction();
 
+      // FIXME: This transformation is not legal unless we can prove
+      // that the callee always terminates.
+#if 0
       // If this call site is dead and it is to a readonly function, we should
       // just delete the call instead of trying to inline it, regardless of
       // size.  This happens because IPSCCP propagates the result out of the
@@ -396,6 +400,7 @@ bool Inliner::runOnSCC(CallGraphSCC &SCC) {
         // Update the cached cost info with the missing call
         growCachedCostInfo(Caller, NULL);
       } else {
+#endif
         // We can only inline direct calls to non-declarations.
         if (Callee == 0 || Callee->isDeclaration()) continue;
       
@@ -437,7 +442,9 @@ bool Inliner::runOnSCC(CallGraphSCC &SCC) {
         
         // Update the cached cost info with the inlined call.
         growCachedCostInfo(Caller, Callee);
+#if 0
       }
+#endif
       
       // If we inlined or deleted the last possible call site to the function,
       // delete the function body now.
diff --git a/test/Transforms/Inline/delete-call.ll b/test/Transforms/Inline/delete-call.ll
index 3505608b828..7775aa383fc 100644
--- a/test/Transforms/Inline/delete-call.ll
+++ b/test/Transforms/Inline/delete-call.ll
@@ -1,6 +1,6 @@
 ; RUN: opt %s -S  -inline -functionattrs -stats |& grep {Number of call sites deleted, not inlined}
 ; RUN: opt %s -S  -inline -stats |& grep {Number of functions inlined}
-
+; XFAIL: *
 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-n8:16:32"
 target triple = "i386-apple-darwin9.8"