; RUN: opt -S -codegenprepare < %s | FileCheck %s --check-prefix=SLOW ; RUN: opt -S -codegenprepare -mattr=+bmi < %s | FileCheck %s --check-prefix=FAST_TZ ; RUN: opt -S -codegenprepare -mattr=+lzcnt < %s | FileCheck %s --check-prefix=FAST_LZ target triple = "x86_64-unknown-unknown" target datalayout = "e-n32:64" ; If the intrinsic is cheap, nothing should change. ; If the intrinsic is expensive, check if the input is zero to avoid the call. ; This is undoing speculation that may have been created by SimplifyCFG + InstCombine. define i64 @cttz(i64 %A) { entry: %z = call i64 @llvm.cttz.i64(i64 %A, i1 false) ret i64 %z ; SLOW-LABEL: @cttz( ; SLOW: entry: ; SLOW: %cmpz = icmp eq i64 %A, 0 ; SLOW: br i1 %cmpz, label %cond.end, label %cond.false ; SLOW: cond.false: ; SLOW: %z = call i64 @llvm.cttz.i64(i64 %A, i1 true) ; SLOW: br label %cond.end ; SLOW: cond.end: ; SLOW: %ctz = phi i64 [ 64, %entry ], [ %z, %cond.false ] ; SLOW: ret i64 %ctz ; FAST_TZ-LABEL: @cttz( ; FAST_TZ: %z = call i64 @llvm.cttz.i64(i64 %A, i1 false) ; FAST_TZ: ret i64 %z } define i64 @ctlz(i64 %A) { entry: %z = call i64 @llvm.ctlz.i64(i64 %A, i1 false) ret i64 %z ; SLOW-LABEL: @ctlz( ; SLOW: entry: ; SLOW: %cmpz = icmp eq i64 %A, 0 ; SLOW: br i1 %cmpz, label %cond.end, label %cond.false ; SLOW: cond.false: ; SLOW: %z = call i64 @llvm.ctlz.i64(i64 %A, i1 true) ; SLOW: br label %cond.end ; SLOW: cond.end: ; SLOW: %ctz = phi i64 [ 64, %entry ], [ %z, %cond.false ] ; SLOW: ret i64 %ctz ; FAST_LZ-LABEL: @ctlz( ; FAST_LZ: %z = call i64 @llvm.ctlz.i64(i64 %A, i1 false) ; FAST_LZ: ret i64 %z } declare i64 @llvm.cttz.i64(i64, i1) declare i64 @llvm.ctlz.i64(i64, i1)