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| author | Paul Redmond <paul.redmond@intel.com> | 2013-02-12 15:21:21 +0000 |
|---|---|---|
| committer | Paul Redmond <paul.redmond@intel.com> | 2013-02-12 15:21:21 +0000 |
| commit | 5c97450df748819381daa4c4d400c39b0d7378ae (patch) | |
| tree | 248ac9d6c584c8abdf1caaab94aba84ca3d24715 /test | |
| parent | 7eacad03efda36e09ebd96e95d7891cadaaa9087 (diff) | |
| download | external_llvm-5c97450df748819381daa4c4d400c39b0d7378ae.zip external_llvm-5c97450df748819381daa4c4d400c39b0d7378ae.tar.gz external_llvm-5c97450df748819381daa4c4d400c39b0d7378ae.tar.bz2 | |
PR14562 - Truncation of left shift became undef
DAGCombiner::ReduceLoadWidth was converting (trunc i32 (shl i64 v, 32))
into (shl i32 v, 32) into undef. To prevent this, check the shift count
against the final result size.
Patch by: Kevin Schoedel
Reviewed by: Nadav Rotem
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174972 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/CodeGen/X86/pr14562.ll | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/test/CodeGen/X86/pr14562.ll b/test/CodeGen/X86/pr14562.ll new file mode 100644 index 0000000..2df64b3 --- /dev/null +++ b/test/CodeGen/X86/pr14562.ll @@ -0,0 +1,15 @@ +; RUN: llc < %s -march=x86 | FileCheck %s + +@temp1 = global i64 -77129852189294865, align 8 + +define void @foo() nounwind { + %x = load i64* @temp1, align 8 + %s = shl i64 %x, 32 + %t = trunc i64 %s to i32 + %z = zext i32 %t to i64 + store i64 %z, i64* @temp1, align 8 +; CHECK: movl $0, temp1+4 +; CHECK: movl $0, temp1 + ret void +} + |