fix PR7429, a crash turning a load from a string into a float.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108113 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index 0c4d850b01c38e5791badf65d4492e8dd267a80b..f7bd19d78ce0ca88f726956f8fc73b14106d73dd 100644 (file)
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -436,8 +436,10 @@ Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C,
     unsigned StrLen = Str.length();
     const Type *Ty = cast<PointerType>(CE->getType())->getElementType();
     unsigned NumBits = Ty->getPrimitiveSizeInBits();
-    // Replace LI with immediate integer store.
-    if ((NumBits >> 3) == StrLen + 1) {
+    // Replace load with immediate integer if the result is an integer or fp
+    // value.
+    if ((NumBits >> 3) == StrLen + 1 && (NumBits & 7) == 0 &&
+        isa<IntegerType>(Ty) || Ty->isFloatingPointTy()) {
       APInt StrVal(NumBits, 0);
       APInt SingleChar(NumBits, 0);
       if (TD->isLittleEndian()) {
@@ -454,7 +456,11 @@ Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C,
         SingleChar = 0;
         StrVal = (StrVal << 8) | SingleChar;
       }
-      return ConstantInt::get(CE->getContext(), StrVal);
+      
+      Constant *Res = ConstantInt::get(CE->getContext(), StrVal);
+      if (Ty->isFloatingPointTy())
+        Res = ConstantExpr::getBitCast(Res, Ty);
+      return Res;
     }
   }
   

diff --git a/test/Transforms/InstCombine/load3.ll b/test/Transforms/InstCombine/load3.ll
index 8d16523c23e0c6430b50ea7c7ad78b4b48067bfe..35398e17db8ccddba891dd46852236a472994011 100644 (file)
--- a/test/Transforms/InstCombine/load3.ll
+++ b/test/Transforms/InstCombine/load3.ll
@@ -1,4 +1,6 @@
 ; RUN: opt < %s -instcombine -S | FileCheck %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-apple-darwin10.0.0"
 
 ; Instcombine should be able to do trivial CSE of loads.
 
@@ -12,3 +14,14 @@ define i32 @test1(i32* %p) {
 ; CHECK: @test1
 ; CHECK: ret i32 0
 }
+
+
+; PR7429
+@.str = private constant [4 x i8] c"XYZ\00"
+define float @test2() {
+  %tmp = load float* bitcast ([4 x i8]* @.str to float*), align 1
+  ret float %tmp
+  
+; CHECK: @test2
+; CHECK: ret float 0x3806965600000000
+}
\ No newline at end of file