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| author | Peter Collingbourne <peter@pcc.me.uk> | 2016-10-21 19:57:55 +0000 |
|---|---|---|
| committer | Peter Collingbourne <peter@pcc.me.uk> | 2016-10-21 19:57:55 +0000 |
| commit | e9bd49824d471b79fd54ae014a998ba3996f9640 (patch) | |
| tree | 9d2ad70e73f639bef709df6a7cd09b38f7754716 /llvm/test/CodeGen/X86 | |
| parent | ab488723134a42e85211d67a591537f2f2ad0ca0 (diff) | |
| download | bcm5719-llvm-e9bd49824d471b79fd54ae014a998ba3996f9640.tar.gz bcm5719-llvm-e9bd49824d471b79fd54ae014a998ba3996f9640.zip | |
X86: Improve BT instruction selection for 64-bit values.
If a 64-bit value is tested against a bit which is known to be in the range
[0..31) (modulo 64), we can use the 32-bit BT instruction, which has a slightly
shorter encoding.
Differential Revision: https://reviews.llvm.org/D25862
llvm-svn: 284864
Diffstat (limited to 'llvm/test/CodeGen/X86')
| -rw-r--r-- | llvm/test/CodeGen/X86/bt.ll | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/X86/bt.ll b/llvm/test/CodeGen/X86/bt.ll index a6705088745..6576f33a5b9 100644 --- a/llvm/test/CodeGen/X86/bt.ll +++ b/llvm/test/CodeGen/X86/bt.ll @@ -596,3 +596,15 @@ define zeroext i1 @invert(i32 %flags, i32 %flag) nounwind { ret i1 %tobool } +define zeroext i1 @extend(i32 %bit, i64 %bits) { +; CHECK-LABEL: extend: +; CHECK: # BB#0: +; CHECK-NEXT: btl %edi, %esi +entry: + %and = and i32 %bit, 31 + %sh_prom = zext i32 %and to i64 + %shl = shl i64 1, %sh_prom + %and1 = and i64 %shl, %bits + %tobool = icmp ne i64 %and1, 0 + ret i1 %tobool +} |
