From eb9f89287e8ff3daeb9191ecd0cc3241a4f4137d Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Sat, 30 Aug 2008 02:03:58 +0000 Subject: Transform (x << (y&31)) -> (x << y). This takes advantage of the fact x86 shift instructions 2nd operand (shift count) is limited to 0 to 31 (or 63 in the x86-64 case). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55558 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/CodeGen/X86/shift-and.ll | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 test/CodeGen/X86/shift-and.ll (limited to 'test/CodeGen/X86') diff --git a/test/CodeGen/X86/shift-and.ll b/test/CodeGen/X86/shift-and.ll new file mode 100644 index 0000000000..b6d78a4857 --- /dev/null +++ b/test/CodeGen/X86/shift-and.ll @@ -0,0 +1,24 @@ +; RUN: llvm-as < %s | llc -march=x86 | grep and | count 1 +; RUN: llvm-as < %s | llc -march=x86-64 | not grep and + +define i32 @t1(i32 %t, i32 %val) nounwind { + %shamt = and i32 %t, 31 + %res = shl i32 %val, %shamt + ret i32 %res +} + +@X = internal global i16 0 + +define void @t2(i16 %t) nounwind { + %shamt = and i16 %t, 31 + %tmp = load i16* @X + %tmp1 = ashr i16 %tmp, %shamt + store i16 %tmp1, i16* @X + ret void +} + +define i64 @t3(i64 %t, i64 %val) nounwind { + %shamt = and i64 %t, 63 + %res = lshr i64 %val, %shamt + ret i64 %res +} -- cgit v1.2.3