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| author | Owen Anderson <resistor@mac.com> | 2010-09-22 22:58:22 +0000 |
|---|---|---|
| committer | Owen Anderson <resistor@mac.com> | 2010-09-22 22:58:22 +0000 |
| commit | 3231d13ddd9157fd66b06240e772774c8f616c8b (patch) | |
| tree | f3121ce5aa7fc08ed4c5521c01d0fefc4d12fdb9 /llvm/test/CodeGen/X86/bit-test-shift.ll | |
| parent | bbb9287080b5625f75836cf706bf28fe968377b3 (diff) | |
| download | bcm5719-llvm-3231d13ddd9157fd66b06240e772774c8f616c8b.tar.gz bcm5719-llvm-3231d13ddd9157fd66b06240e772774c8f616c8b.zip | |
A select between a constant and zero, when fed by a bit test, can be efficiently
lowered using a series of shifts.
Fixes <rdar://problem/8285015>.
llvm-svn: 114599
Diffstat (limited to 'llvm/test/CodeGen/X86/bit-test-shift.ll')
| -rw-r--r-- | llvm/test/CodeGen/X86/bit-test-shift.ll | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/X86/bit-test-shift.ll b/llvm/test/CodeGen/X86/bit-test-shift.ll new file mode 100644 index 00000000000..7497613f256 --- /dev/null +++ b/llvm/test/CodeGen/X86/bit-test-shift.ll @@ -0,0 +1,13 @@ +; RUN: llc < %s -march=x86 | FileCheck %s +; <rdar://problem/8285015> + +define i32 @x(i32 %t) nounwind readnone ssp { +entry: +; CHECK: shll $23, %eax +; CHECK: sarl $31, %eax +; CHECK: andl $-26, %eax + %and = and i32 %t, 256 + %tobool = icmp eq i32 %and, 0 + %retval.0 = select i1 %tobool, i32 0, i32 -26 + ret i32 %retval.0 +} |
