; RUN: llc < %s -march=x86 -mcpu=yonah | FileCheck %s declare i32 @llvm.cttz.i32(i32, i1) declare i16 @llvm.ctlz.i16(i16, i1) declare i32 @llvm.ctlz.i32(i32, i1) define i32 @cttz_i32(i32 %x) { %tmp = call i32 @llvm.cttz.i32( i32 %x, i1 true ) ret i32 %tmp ; CHECK: cttz_i32: ; CHECK: bsfl ; CHECK-NOT: cmov ; CHECK: ret } define i16 @ctlz_i16(i16 %x, i16 %y) { entry: %tmp1 = add i16 %x, %y %tmp2 = call i16 @llvm.ctlz.i16( i16 %tmp1, i1 true ) ret i16 %tmp2 ; CHECK: ctlz_i16: ; CHECK: bsrw ; CHECK-NOT: cmov ; CHECK: xorl $15, ; CHECK: ret } define i32 @ctlz_i32(i32 %x) { %tmp = call i32 @llvm.ctlz.i32( i32 %x, i1 true ) ret i32 %tmp ; CHECK: ctlz_i32: ; CHECK: bsrl ; CHECK-NOT: cmov ; CHECK: xorl $31, ; CHECK: ret } define i32 @ctlz_i32_cmov(i32 %n) { entry: ; Generate a cmov to handle zero inputs when necessary. ; CHECK: ctlz_i32_cmov: ; CHECK: bsrl ; CHECK: cmov ; CHECK: xorl $31, ; CHECK: ret %tmp1 = call i32 @llvm.ctlz.i32(i32 %n, i1 false) ret i32 %tmp1 } define i32 @ctlz_i32_fold_cmov(i32 %n) { entry: ; Don't generate the cmovne when the source is known non-zero (and bsr would ; not set ZF). ; rdar://9490949 ; CHECK: ctlz_i32_fold_cmov: ; CHECK: bsrl ; CHECK-NOT: cmov ; CHECK: xorl $31, ; CHECK: ret %or = or i32 %n, 1 %tmp1 = call i32 @llvm.ctlz.i32(i32 %or, i1 false) ret i32 %tmp1 } define i32 @ctlz_bsr(i32 %n) { entry: ; Don't generate any xors when a 'ctlz' intrinsic is actually used to compute ; the most significant bit, which is what 'bsr' does natively. ; CHECK: ctlz_bsr: ; CHECK: bsrl ; CHECK-NOT: xorl ; CHECK: ret %ctlz = call i32 @llvm.ctlz.i32(i32 %n, i1 true) %bsr = xor i32 %ctlz, 31 ret i32 %bsr } define i32 @ctlz_bsr_cmov(i32 %n) { entry: ; Same as ctlz_bsr, but ensure this happens even when there is a potential ; zero. ; CHECK: ctlz_bsr_cmov: ; CHECK: bsrl ; CHECK-NOT: xorl ; CHECK: ret %ctlz = call i32 @llvm.ctlz.i32(i32 %n, i1 false) %bsr = xor i32 %ctlz, 31 ret i32 %bsr }