OSchip
/
llvm-project
mirror of https://github.com/THU-DSP-LAB/llvm-project.git
13
0
Fork 2
Code Issues Packages Projects Releases Wiki Activity

[DAG] canCreateUndefOrPoison - add freeze(ctpop(x)) -> ctpop(freeze(x)) and freeze(parity(x)) -> parity(freeze(x)) support 

Both are guaranteed not to create undef/poison
This commit is contained in:
Simon Pilgrim 2022-08-09 10:10:29 +01:00
parent af0052ef74
commit 2724143551
2 changed files with 6 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
View File

@ -4562,7 +4562,9 @@ bool SelectionDAG::canCreateUndefOrPoison(SDValue Op, const APInt &DemandedElts,
switch (Opcode) {
case ISD::FREEZE:
case ISD::BSWAP:
case ISD::CTPOP:
case ISD::BITREVERSE:
case ISD::PARITY:
case ISD::SIGN_EXTEND:
case ISD::ZERO_EXTEND:
case ISD::BITCAST:

36
llvm/test/CodeGen/X86/freeze-unary.ll
View File

@ -130,39 +130,14 @@ declare <4 x i32> @llvm.bitreverse.v4i32(<4 x i32>)
define i8 @freeze_ctpop(i8 %a0) nounwind {
; X86-LABEL: freeze_ctpop:
; X86: # %bb.0:
; X86-NEXT: movzbl {{[0-9]+}}(%esp), %ecx
; X86-NEXT: movl %ecx, %eax
; X86-NEXT: shrb %al
; X86-NEXT: andb $85, %al
; X86-NEXT: subb %al, %cl
; X86-NEXT: movl %ecx, %eax
; X86-NEXT: andb $51, %al
; X86-NEXT: shrb $2, %cl
; X86-NEXT: andb $51, %cl
; X86-NEXT: addb %al, %cl
; X86-NEXT: movl %ecx, %eax
; X86-NEXT: shrb $4, %al
; X86-NEXT: addb %cl, %al
; X86-NEXT: andb $15, %al
; X86-NEXT: andb $1, %al
; X86-NEXT: cmpb $0, {{[0-9]+}}(%esp)
; X86-NEXT: setnp %al
; X86-NEXT: retl
;
; X64-LABEL: freeze_ctpop:
; X64: # %bb.0:
; X64-NEXT: movl %edi, %eax
; X64-NEXT: shrb %al
; X64-NEXT: andb $85, %al
; X64-NEXT: subb %al, %dil
; X64-NEXT: movl %edi, %ecx
; X64-NEXT: andb $51, %cl
; X64-NEXT: shrb $2, %dil
; X64-NEXT: andb $51, %dil
; X64-NEXT: addb %dil, %cl
; X64-NEXT: movl %ecx, %eax
; X64-NEXT: shrb $4, %al
; X64-NEXT: addb %cl, %al
; X64-NEXT: andb $15, %al
; X64-NEXT: andb $1, %al
; X64-NEXT: testb %dil, %dil
; X64-NEXT: setnp %al
; X64-NEXT: retq
%x = call i8 @llvm.ctpop.i8(i8 %a0)
%y = freeze i8 %x
@ -188,7 +163,6 @@ define <16 x i8> @freeze_ctpop_vec(<16 x i8> %a0) nounwind {
; X86-NEXT: psrlw $4, %xmm1
; X86-NEXT: paddb %xmm1, %xmm0
; X86-NEXT: pand {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0
; X86-NEXT: pand {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0
; X86-NEXT: retl
;
; X64-LABEL: freeze_ctpop_vec:
@ -219,14 +193,12 @@ define i8 @freeze_parity(i8 %a0) nounwind {
; X86: # %bb.0:
; X86-NEXT: cmpb $0, {{[0-9]+}}(%esp)
; X86-NEXT: setnp %al
; X86-NEXT: andb $1, %al
; X86-NEXT: retl
;
; X64-LABEL: freeze_parity:
; X64: # %bb.0:
; X64-NEXT: testb %dil, %dil
; X64-NEXT: setnp %al
; X64-NEXT: andb $1, %al
; X64-NEXT: retq
%x = call i8 @llvm.ctpop.i8(i8 %a0)
%y = and i8 %x, 1