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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 | ed1088afb51189efff02886891c4e25a5a5fb5f9 (patch) | |
| tree | 77c254b149028b8cb963b08778b9f8155930e796 /test | |
| parent | 4af1eaee70a8de71f805ef7c3eca581ff6a014e8 (diff) | |
| download | llvm-ed1088afb51189efff02886891c4e25a5a5fb5f9.tar.gz llvm-ed1088afb51189efff02886891c4e25a5a5fb5f9.tar.bz2 llvm-ed1088afb51189efff02886891c4e25a5a5fb5f9.tar.xz | |
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>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114599 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/CodeGen/X86/bit-test-shift.ll | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/test/CodeGen/X86/bit-test-shift.ll b/test/CodeGen/X86/bit-test-shift.ll new file mode 100644 index 0000000000..7497613f25 --- /dev/null +++ b/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 +} |