[X86] Add PTEST tests showing failure to extract allsign cases

As discussed on PR42035, we can often use MOVMSK to avoid a cmpgt/ashr by just analysing the extracted signbits.
This commit is contained in:
Simon Pilgrim 2020-05-25 15:33:44 +01:00
parent c8b7c73c57
commit a6c4cd3bcb
1 changed files with 98 additions and 1 deletions

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@ -1,5 +1,6 @@
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+avx | FileCheck %s
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+avx | FileCheck %s --check-prefixes=CHECK,AVX1
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+avx2 | FileCheck %s --check-prefixes=CHECK,AVX2
;
; testz(~X,Y) -> testc(X,Y)
@ -297,6 +298,102 @@ start:
ret i1 %6
}
;
; TODO: testz(ashr(X,bw-1),-1) -> movmsk(X)
;
define i32 @ptestz_v2i64_signbits(<2 x i64> %c, i32 %a, i32 %b) {
; CHECK-LABEL: ptestz_v2i64_signbits:
; CHECK: # %bb.0:
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: vpxor %xmm1, %xmm1, %xmm1
; CHECK-NEXT: vpcmpgtq %xmm0, %xmm1, %xmm0
; CHECK-NEXT: vptest %xmm0, %xmm0
; CHECK-NEXT: cmovnel %esi, %eax
; CHECK-NEXT: retq
%t1 = ashr <2 x i64> %c, <i64 63, i64 63>
%t2 = call i32 @llvm.x86.sse41.ptestz(<2 x i64> %t1, <2 x i64> <i64 -1, i64 -1>)
%t3 = icmp ne i32 %t2, 0
%t4 = select i1 %t3, i32 %a, i32 %b
ret i32 %t4
}
define i32 @ptestz_v8i32_signbits(<8 x i32> %c, i32 %a, i32 %b) {
; AVX1-LABEL: ptestz_v8i32_signbits:
; AVX1: # %bb.0:
; AVX1-NEXT: movl %edi, %eax
; AVX1-NEXT: vpsrad $31, %xmm0, %xmm1
; AVX1-NEXT: vextractf128 $1, %ymm0, %xmm0
; AVX1-NEXT: vpsrad $31, %xmm0, %xmm0
; AVX1-NEXT: vinsertf128 $1, %xmm0, %ymm1, %ymm0
; AVX1-NEXT: vptest %ymm0, %ymm0
; AVX1-NEXT: cmovnel %esi, %eax
; AVX1-NEXT: vzeroupper
; AVX1-NEXT: retq
;
; AVX2-LABEL: ptestz_v8i32_signbits:
; AVX2: # %bb.0:
; AVX2-NEXT: movl %edi, %eax
; AVX2-NEXT: vpsrad $31, %ymm0, %ymm0
; AVX2-NEXT: vptest %ymm0, %ymm0
; AVX2-NEXT: cmovnel %esi, %eax
; AVX2-NEXT: vzeroupper
; AVX2-NEXT: retq
%t1 = ashr <8 x i32> %c, <i32 31, i32 31, i32 31, i32 31, i32 31, i32 31, i32 31, i32 31>
%t2 = bitcast <8 x i32> %t1 to <4 x i64>
%t3 = call i32 @llvm.x86.avx.ptestz.256(<4 x i64> %t2, <4 x i64> <i64 -1, i64 -1, i64 -1, i64 -1>)
%t4 = icmp ne i32 %t3, 0
%t5 = select i1 %t4, i32 %a, i32 %b
ret i32 %t5
}
define i32 @ptestz_v8i16_signbits(<8 x i16> %c, i32 %a, i32 %b) {
; CHECK-LABEL: ptestz_v8i16_signbits:
; CHECK: # %bb.0:
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: vpsraw $15, %xmm0, %xmm0
; CHECK-NEXT: vptest %xmm0, %xmm0
; CHECK-NEXT: cmovnel %esi, %eax
; CHECK-NEXT: retq
%t1 = ashr <8 x i16> %c, <i16 15, i16 15, i16 15, i16 15, i16 15, i16 15, i16 15, i16 15>
%t2 = bitcast <8 x i16> %t1 to <2 x i64>
%t3 = call i32 @llvm.x86.sse41.ptestz(<2 x i64> %t2, <2 x i64> <i64 -1, i64 -1>)
%t4 = icmp ne i32 %t3, 0
%t5 = select i1 %t4, i32 %a, i32 %b
ret i32 %t5
}
define i32 @ptestz_v32i8_signbits(<32 x i8> %c, i32 %a, i32 %b) {
; AVX1-LABEL: ptestz_v32i8_signbits:
; AVX1: # %bb.0:
; AVX1-NEXT: movl %edi, %eax
; AVX1-NEXT: vextractf128 $1, %ymm0, %xmm1
; AVX1-NEXT: vpxor %xmm2, %xmm2, %xmm2
; AVX1-NEXT: vpcmpgtb %xmm1, %xmm2, %xmm1
; AVX1-NEXT: vpcmpgtb %xmm0, %xmm2, %xmm0
; AVX1-NEXT: vinsertf128 $1, %xmm1, %ymm0, %ymm0
; AVX1-NEXT: vptest %ymm0, %ymm0
; AVX1-NEXT: cmovnel %esi, %eax
; AVX1-NEXT: vzeroupper
; AVX1-NEXT: retq
;
; AVX2-LABEL: ptestz_v32i8_signbits:
; AVX2: # %bb.0:
; AVX2-NEXT: movl %edi, %eax
; AVX2-NEXT: vpxor %xmm1, %xmm1, %xmm1
; AVX2-NEXT: vpcmpgtb %ymm0, %ymm1, %ymm0
; AVX2-NEXT: vptest %ymm0, %ymm0
; AVX2-NEXT: cmovnel %esi, %eax
; AVX2-NEXT: vzeroupper
; AVX2-NEXT: retq
%t1 = ashr <32 x i8> %c, <i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7>
%t2 = bitcast <32 x i8> %t1 to <4 x i64>
%t3 = call i32 @llvm.x86.avx.ptestz.256(<4 x i64> %t2, <4 x i64> <i64 -1, i64 -1, i64 -1, i64 -1>)
%t4 = icmp ne i32 %t3, 0
%t5 = select i1 %t4, i32 %a, i32 %b
ret i32 %t5
}
declare i32 @llvm.x86.sse41.ptestz(<2 x i64>, <2 x i64>) nounwind readnone
declare i32 @llvm.x86.sse41.ptestc(<2 x i64>, <2 x i64>) nounwind readnone
declare i32 @llvm.x86.sse41.ptestnzc(<2 x i64>, <2 x i64>) nounwind readnone