StackColoring: don't clear an instruction's mem operand if the underlying

object is a PseudoSourceValue and PseudoSourceValue::isConstant returns true (i.e.,
points to memory that has a constant value).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181751 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/StackColoring.cpp b/lib/CodeGen/StackColoring.cpp
index a789a2596dbf719da445262e0ef34e52b357f980..90b93aaa72480b6e4cc1cfcac4548e91b5479d13 100644 (file)
--- a/lib/CodeGen/StackColoring.cpp
+++ b/lib/CodeGen/StackColoring.cpp
@@ -42,6 +42,7 @@
 #include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/PseudoSourceValue.h"
 #include "llvm/CodeGen/SlotIndexes.h"
 #include "llvm/DebugInfo.h"
 #include "llvm/IR/Function.h"
@@ -528,6 +529,10 @@ void StackColoring::remapInstructions(DenseMap<int, int> &SlotRemap) {
         if (!V)
           continue;
 
+        const PseudoSourceValue *PSV = dyn_cast<const PseudoSourceValue>(V);
+        if (PSV && PSV->isConstant(MFI))
+          continue;
+
         // Climb up and find the original alloca.
         V = GetUnderlyingObject(V);
         // If we did not find one, or if the one that we found is not in our

diff --git a/test/CodeGen/Mips/stackcoloring.ll b/test/CodeGen/Mips/stackcoloring.ll
new file mode 100644 (file)
index 0000000..76cc086
--- /dev/null
+++ b/test/CodeGen/Mips/stackcoloring.ll
@@ -0,0 +1,39 @@
+; RUN: llc -march=mipsel < %s | FileCheck %s
+
+@g1 = external global i32*
+
+; CHECK: foo1:
+; CHECK: lw ${{[0-9]+}}, %got(g1)
+; CHECK: # %for.body
+; CHECK: # %for.end
+
+define i32 @foo1() {
+entry:
+  %b = alloca [16 x i32], align 4
+  %0 = bitcast [16 x i32]* %b to i8*
+  call void @llvm.lifetime.start(i64 64, i8* %0)
+  %arraydecay = getelementptr inbounds [16 x i32]* %b, i32 0, i32 0
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %i.05 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+  %v.04 = phi i32 [ 0, %entry ], [ %add, %for.body ]
+  %1 = load i32** @g1, align 4
+  %arrayidx = getelementptr inbounds i32* %1, i32 %i.05
+  %2 = load i32* %arrayidx, align 4
+  %call = call i32 @foo2(i32 %2, i32* %arraydecay)
+  %add = add nsw i32 %call, %v.04
+  %inc = add nsw i32 %i.05, 1
+  %exitcond = icmp eq i32 %inc, 10000
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  call void @llvm.lifetime.end(i64 64, i8* %0)
+  ret i32 %add
+}
+
+declare void @llvm.lifetime.start(i64, i8* nocapture)
+
+declare i32 @foo2(i32, i32*)
+
+declare void @llvm.lifetime.end(i64, i8* nocapture)