llvm-mirror/test/CodeGen/AArch64/arm64-clrsb.ll
Jessica Paquette f7efb97beb [GlobalISel][AArch64] Legalize + select some llvm.ctlz.* intrinsics
Legalize/select llvm.ctlz.*

Add select-ctlz to show that we actually select them. Update arm64-clrsb.ll and
arm64-vclz.ll to show that we perform valid transformations in optimized builds,
and document where GISel can improve.

Differential Revision: https://reviews.llvm.org/D58155

llvm-svn: 354299
2019-02-18 23:33:24 +00:00

46 lines
1.3 KiB
LLVM

; RUN: llc < %s -mtriple=arm64-apple-ios7.0.0 | FileCheck %s
; RUN: llc < %s -mtriple=arm64-apple-ios7.0.0 -O0 -pass-remarks-missed=gisel* -global-isel-abort=2 | FileCheck %s --check-prefixes=GISEL,FALLBACK
target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
; Function Attrs: nounwind readnone
declare i32 @llvm.ctlz.i32(i32, i1) #0
declare i64 @llvm.ctlz.i64(i64, i1) #1
; Function Attrs: nounwind ssp
; FALLBACK-NOT: remark{{.*}}clrsb32
define i32 @clrsb32(i32 %x) #2 {
entry:
%shr = ashr i32 %x, 31
%xor = xor i32 %shr, %x
%mul = shl i32 %xor, 1
%add = or i32 %mul, 1
%0 = tail call i32 @llvm.ctlz.i32(i32 %add, i1 false)
ret i32 %0
; CHECK-LABEL: clrsb32
; CHECK: cls [[TEMP:w[0-9]+]], [[TEMP]]
; FIXME: We should produce the same result here to save some code size. After
; that, we can remove the GISEL special casing.
; GISEL-LABEL: clrsb32
; GISEL: clz
}
; Function Attrs: nounwind ssp
; FALLBACK-NOT: remark{{.*}}clrsb64
define i64 @clrsb64(i64 %x) #3 {
entry:
%shr = ashr i64 %x, 63
%xor = xor i64 %shr, %x
%mul = shl nsw i64 %xor, 1
%add = or i64 %mul, 1
%0 = tail call i64 @llvm.ctlz.i64(i64 %add, i1 false)
ret i64 %0
; CHECK-LABEL: clrsb64
; CHECK: cls [[TEMP:x[0-9]+]], [[TEMP]]
; GISEL-LABEL: clrsb64
; GISEL: cls [[TEMP:x[0-9]+]], [[TEMP]]
}