diff options
| author | Dale Johannesen <dalej@apple.com> | 2009-02-11 19:19:41 +0000 |
|---|---|---|
| committer | Dale Johannesen <dalej@apple.com> | 2009-02-11 19:19:41 +0000 |
| commit | 0ca3f130fadb912319a80c849ffa0eae16f0ecb4 (patch) | |
| tree | 1e4731af3bbc428927b3ce38e7fc4f5a4b626ad1 /test | |
| parent | a60551ce6b30d2e8dd7445d64f7d7277ae0c7bcf (diff) | |
| download | external_llvm-0ca3f130fadb912319a80c849ffa0eae16f0ecb4.zip external_llvm-0ca3f130fadb912319a80c849ffa0eae16f0ecb4.tar.gz external_llvm-0ca3f130fadb912319a80c849ffa0eae16f0ecb4.tar.bz2 | |
Make a transformation added in 63266 a bit less aggressive.
It was transforming (x&y)==y to (x&y)!=0 in the case where
y is variable and known to have at most one bit set (e.g. z&1).
This is not correct; the expressions are not equivalent when y==0.
I believe this patch salvages what can be salvaged, including
all the cases in bt.ll. Dan, please review.
Fixes gcc.c-torture/execute/20040709-[12].c
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64314 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/CodeGen/X86/nobt.ll | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/test/CodeGen/X86/nobt.ll b/test/CodeGen/X86/nobt.ll new file mode 100644 index 0000000..5529428 --- /dev/null +++ b/test/CodeGen/X86/nobt.ll @@ -0,0 +1,70 @@ +; RUN: llvm-as < %s | llc -march=x86 | not grep btl + +; This tests some cases where BT must not be generated. See also bt.ll. +; Fixes 20040709-[12].c in gcc testsuite. + +define void @test2(i32 %x, i32 %n) nounwind { +entry: + %tmp1 = and i32 %x, 1 + %tmp2 = urem i32 %tmp1, 15 + %tmp3 = and i32 %tmp2, 1 ; <i32> [#uses=1] + %tmp4 = icmp eq i32 %tmp3, %tmp2 ; <i1> [#uses=1] + br i1 %tmp4, label %bb, label %UnifiedReturnBlock + +bb: ; preds = %entry + call void @foo() + ret void + +UnifiedReturnBlock: ; preds = %entry + ret void +} + +define void @test3(i32 %x, i32 %n) nounwind { +entry: + %tmp1 = and i32 %x, 1 + %tmp2 = urem i32 %tmp1, 15 + %tmp3 = and i32 %tmp2, 1 ; <i32> [#uses=1] + %tmp4 = icmp eq i32 %tmp2, %tmp3 ; <i1> [#uses=1] + br i1 %tmp4, label %bb, label %UnifiedReturnBlock + +bb: ; preds = %entry + call void @foo() + ret void + +UnifiedReturnBlock: ; preds = %entry + ret void +} + +define void @test4(i32 %x, i32 %n) nounwind { +entry: + %tmp1 = and i32 %x, 1 + %tmp2 = urem i32 %tmp1, 15 + %tmp3 = and i32 %tmp2, 1 ; <i32> [#uses=1] + %tmp4 = icmp ne i32 %tmp2, %tmp3 ; <i1> [#uses=1] + br i1 %tmp4, label %bb, label %UnifiedReturnBlock + +bb: ; preds = %entry + call void @foo() + ret void + +UnifiedReturnBlock: ; preds = %entry + ret void +} + +define void @test5(i32 %x, i32 %n) nounwind { +entry: + %tmp1 = and i32 %x, 1 + %tmp2 = urem i32 %tmp1, 15 + %tmp3 = and i32 %tmp2, 1 ; <i32> [#uses=1] + %tmp4 = icmp ne i32 %tmp2, %tmp3 ; <i1> [#uses=1] + br i1 %tmp4, label %bb, label %UnifiedReturnBlock + +bb: ; preds = %entry + call void @foo() + ret void + +UnifiedReturnBlock: ; preds = %entry + ret void +} + +declare void @foo() |