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| author | Chris Lattner <sabre@nondot.org> | 2007-07-15 20:54:51 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2007-07-15 20:54:51 +0000 |
| commit | 4241e4da85caf46d1f6457e99029dd37cc27be72 (patch) | |
| tree | efd1bfb2406bca0aa5dd42bcb3d4840e4d286218 /test | |
| parent | a0141b90a34da612e348e2c7af41ec571a6fd143 (diff) | |
| download | llvm-4241e4da85caf46d1f6457e99029dd37cc27be72.tar.gz llvm-4241e4da85caf46d1f6457e99029dd37cc27be72.tar.bz2 llvm-4241e4da85caf46d1f6457e99029dd37cc27be72.tar.xz | |
Implement shift-simplify.ll:test[45].
First teach instcombine that sign bit checks only demand the
sign bit, this allows simplify demanded bits to hack on
expressions better.
Second, teach instcombine that ashr is useless if only the
sign bit is demanded.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39880 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/Transforms/InstCombine/shift-simplify.ll | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/shift-simplify.ll b/test/Transforms/InstCombine/shift-simplify.ll index 4c84612748..e028385839 100644 --- a/test/Transforms/InstCombine/shift-simplify.ll +++ b/test/Transforms/InstCombine/shift-simplify.ll @@ -28,3 +28,15 @@ define i1 @test3(i32 %X) { ret i1 %tmp2 } +define i1 @test4(i32 %X) { + %tmp1 = lshr i32 %X, 7 + %tmp2 = icmp slt i32 %tmp1, 0 + ret i1 %tmp2 +} + +define i1 @test5(i32 %X) { + %tmp1 = ashr i32 %X, 7 + %tmp2 = icmp slt i32 %tmp1, 0 + ret i1 %tmp2 +} + |