From: Nick Lewycky <nicholas@mxc.ca>
Date: Wed, 8 May 2013 09:00:10 +0000 (+0000)
Subject: Fix a bug in codegenprep where it was losing track of values OptimizeMemoryInst
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=ae9f07e0b8332181e9a79cffc7dea99f3bc9bea8;p=oota-llvm.git

Fix a bug in codegenprep where it was losing track of values OptimizeMemoryInst
by switching to a ValueMap. Patch by Andrea DiBiagio!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181397 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/CodeGenPrepare.cpp b/lib/Transforms/Scalar/CodeGenPrepare.cpp
index 615c5174492..f0d29c88a82 100644
--- a/lib/Transforms/Scalar/CodeGenPrepare.cpp
+++ b/lib/Transforms/Scalar/CodeGenPrepare.cpp
@@ -18,6 +18,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/ValueMap.h"
 #include "llvm/Analysis/DominatorInternals.h"
 #include "llvm/Analysis/Dominators.h"
 #include "llvm/Analysis/InstructionSimplify.h"
@@ -88,7 +89,7 @@ namespace {
     /// Keeps track of non-local addresses that have been sunk into a block.
     /// This allows us to avoid inserting duplicate code for blocks with
     /// multiple load/stores of the same address.
-    DenseMap<Value*, Value*> SunkAddrs;
+    ValueMap<Value*, Value*> SunkAddrs;
 
     /// ModifiedDT - If CFG is modified in anyway, dominator tree may need to
     /// be updated.
@@ -1653,10 +1654,6 @@ bool CodeGenPrepare::OptimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
       // start of the block.
       CurInstIterator = BB->begin();
       SunkAddrs.clear();
-    } else {
-      // This address is now available for reassignment, so erase the table
-      // entry; we don't want to match some completely different instruction.
-      SunkAddrs[Addr] = 0;
     }
   }
   ++NumMemoryInsts;
diff --git a/test/CodeGen/X86/codegen-prepare.ll b/test/CodeGen/X86/codegen-prepare.ll
new file mode 100644
index 00000000000..e8ee0706353
--- /dev/null
+++ b/test/CodeGen/X86/codegen-prepare.ll
@@ -0,0 +1,44 @@
+; RUN: llc < %s -mtriple=x86_64-pc-linux | FileCheck %s
+
+; Check that the CodeGenPrepare Pass
+; does not wrongly rewrite the address computed by Instruction %4
+; as [12 + Base:%this].
+
+; This test makes sure that:
+; - both the store and the first load instructions
+;   within basic block labeled 'if.then' are not removed. 
+; - the store instruction stores a value at address [60 + %this]
+; - the first load instruction loads a value at address [12 + %this]
+
+%class.A = type { %struct.B }
+%struct.B = type { %class.C, %class.D, %class.C, %class.D }
+%class.C = type { float, float, float }
+%class.D = type { [3 x %class.C] }
+
+define linkonce_odr void @foo(%class.A* nocapture %this, i32 %BoolValue) nounwind uwtable {
+entry:
+  %cmp = icmp eq i32 %BoolValue, 0
+  %address1 = getelementptr inbounds %class.A* %this, i64 0, i32 0, i32 3
+  %address2 = getelementptr inbounds %class.A* %this, i64 0, i32 0, i32 1
+  br i1 %cmp, label %if.else, label %if.then
+
+if.then:                                         ; preds = %entry
+  %0 = getelementptr inbounds %class.D* %address2, i64 0, i32 0, i64 0, i32 0
+  %1 = load float* %0, align 4 
+  %2 = getelementptr inbounds float* %0, i64 3
+  %3 = load float* %2, align 4 
+  %4 = getelementptr inbounds %class.D* %address1, i64 0, i32 0, i64 0, i32 0
+  store float %1, float* %4, align 4
+  br label %if.end
+
+if.else:                                          ; preds = %entry
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %if.else, %entry
+  ret void
+}
+
+; CHECK: foo:
+; CHECK: movss 12([[THIS:%[a-zA-Z0-9]+]]), [[REGISTER:%[a-zA-Z0-9]+]]
+; CHECK-NEXT: movss [[REGISTER]], 60([[THIS]])
+