Re-commit 97860 with fix. getMallocAllocatedType may return null.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98000 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index e2b7d3d60db822f60dae1b07702a6fa9a5d89078..0582210d40721215962a9ca290f4d8d2c429bd20 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -337,6 +337,16 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
         }
         return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy, AllocaSize));
       }
+    } else if (CallInst *MI = extractMallocCall(Op1)) {
+      const Type* MallocType = getMallocAllocatedType(MI);
+      // Get alloca size.
+      if (MallocType && MallocType->isSized()) {
+        if (Value *NElems = getMallocArraySize(MI, TD, true)) {
+          if (ConstantInt *NElements = dyn_cast<ConstantInt>(NElems))
+        return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy,
+               (NElements->getZExtValue() * TD->getTypeAllocSize(MallocType))));
+        }
+      }
     } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Op1)) {      
       // Only handle constant GEPs here.
       if (CE->getOpcode() != Instruction::GetElementPtr) break;

diff --git a/test/Transforms/InstCombine/objsize.ll b/test/Transforms/InstCombine/objsize.ll
index 57dc2fd054428af8cc0b8c0bf879b784c05e8100..cd7b7c80679b9ac913a2087eadc91338b36383df 100644 (file)
--- a/test/Transforms/InstCombine/objsize.ll
+++ b/test/Transforms/InstCombine/objsize.ll
@@ -118,8 +118,24 @@ entry:
   ret i32 0
 }
 
+@s = external global i8*
+
+define void @test5(i32 %n) nounwind ssp {
+; CHECK: @test5
+entry:
+  %0 = tail call noalias i8* @malloc(i32 20) nounwind
+  %1 = tail call i32 @llvm.objectsize.i32(i8* %0, i1 false)
+  %2 = load i8** @s, align 8
+; CHECK-NOT: @llvm.objectsize
+; CHECK: @__memcpy_chk(i8* %0, i8* %1, i32 10, i32 20)
+  %3 = tail call i8* @__memcpy_chk(i8* %0, i8* %2, i32 10, i32 %1) nounwind
+  ret void
+}
+
 declare i8* @__memset_chk(i8*, i32, i64, i64) nounwind
 
+declare noalias i8* @malloc(i32) nounwind
+
 declare i32 @llvm.objectsize.i32(i8*, i1) nounwind readonly
 
 declare i64 @llvm.objectsize.i64(i8*, i1) nounwind readonly