fix infinite loop in instcombine with more than 4GB memcpy

- memcpy size is wrongly truncated into 32-bit and treat 8GB memcpy is
  0-sized memcpy
- as 0-sized memcpy/memset is already removed before SimplifyMemTransfer
  and SimplifyMemSet in visitCallInst, replace 0 checking with
  assertions.
- replace getZExtValue() with getLimitedValue() according to
  Eli Friedman



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161923 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 0 deletions

diff --git a/test/Transforms/InstCombine/memcpy.ll b/test/Transforms/InstCombine/memcpy.ll
index 8a2e3aa..3a68ff9 100644
--- a/test/Transforms/InstCombine/memcpy.ll
+++ b/test/Transforms/InstCombine/memcpy.ll
@@ -1,6 +1,7 @@
 ; RUN: opt < %s -instcombine -S | FileCheck %s
 
 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
 
 define void @test1(i8* %a) {
         tail call void @llvm.memcpy.p0i8.p0i8.i32(i8* %a, i8* %a, i32 100, i32 1, i1 false)
@@ -17,3 +18,10 @@ define void @test2(i8* %a) {
 ; CHECK: define void @test2
 ; CHECK-NEXT: call void @llvm.memcpy
 }
+
+define void @test3(i8* %d, i8* %s) {
+        tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %d, i8* %s, i64 17179869184, i32 4, i1 false)
+        ret void
+; CHECK: define void @test3
+; CHECK-NEXT: call void @llvm.memcpy
+}