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Differential D101662

[X86] Promote 16-bit CTTZ_ZERO_UNDEF to 32-bit variant
ClosedPublic

Authored by xbolva00 on Apr 30 2021, 1:43 PM.

Details

Reviewers
craig.topper
RKSimon
Commits
rG2af95a527580: [X86] Promote 16-bit CTTZ_ZERO_UNDEF to 32-bit variant
Summary

Related to PR50172.

Protects us against regressions after we will start doing cttz(zext(x)) -> zext(cttz(x)) transformation in the middle-end.

Diff Detail

Event Timeline

xbolva00 created this revision.Apr 30 2021, 1:43 PM
Herald added subscribers: pengfei, hiraditya. · View Herald TranscriptApr 30 2021, 1:43 PM
xbolva00 requested review of this revision.Apr 30 2021, 1:43 PM
Herald added a project: Restricted Project. · View Herald TranscriptApr 30 2021, 1:43 PM
Herald added a subscriber: llvm-commits. · View Herald Transcript
craig.topper added inline comments.Apr 30 2021, 2:20 PM
llvm/lib/Target/X86/X86ISelLowering.cpp
373

Make this an else instead of repeating the BMI check?

xbolva00 updated this revision to Diff 342064.Apr 30 2021, 3:18 PM

Changed to if-else.

xbolva00 updated this revision to Diff 342066.Apr 30 2021, 3:18 PM
xbolva00 marked an inline comment as done.
craig.topper accepted this revision.Apr 30 2021, 3:25 PM

LGTM

This revision is now accepted and ready to land.Apr 30 2021, 3:25 PM
This revision was landed with ongoing or failed builds.Apr 30 2021, 3:42 PM
Closed by commit rG2af95a527580: [X86] Promote 16-bit CTTZ_ZERO_UNDEF to 32-bit variant (authored by xbolva00). · Explain Why
This revision was automatically updated to reflect the committed changes.
xbolva00 added a commit: rG2af95a527580: [X86] Promote 16-bit CTTZ_ZERO_UNDEF to 32-bit variant.
Harbormaster completed remote builds in B102010: Diff 342028.Apr 30 2021, 4:15 PM
Harbormaster completed remote builds in B102039: Diff 342066.Apr 30 2021, 5:32 PM
Harbormaster completed remote builds in B102037: Diff 342064.Apr 30 2021, 6:27 PM
xbolva00 mentioned this in D101582: [InstCombine] cttz(zext(x)) -> zext(cttz(x)) if the 'ZeroIsUndef' parameter is 'true' (PR50172).May 1 2021, 7:13 AM

Revision Contents

PathSize
llvm/
lib/
Target/
X86/
6 lines
test/
CodeGen/
X86/
6 lines

Diff 342028

llvm/lib/Target/X86/X86ISelLowering.cpp

  • This file is larger than 256 KB, so syntax highlighting is disabled by default.
Show First 20 Lines • Show All 358 Lines • ▼ Show 20 LinesX86TargetLowering::X86TargetLowering(const X86TargetMachine &TM,
setOperationAction(ISD::FREM , MVT::f80 , Expand); setOperationAction(ISD::FREM , MVT::f80 , Expand);
setOperationAction(ISD::FREM , MVT::f128 , Expand); setOperationAction(ISD::FREM , MVT::f128 , Expand);
setOperationAction(ISD::FLT_ROUNDS_ , MVT::i32 , Custom); setOperationAction(ISD::FLT_ROUNDS_ , MVT::i32 , Custom);
// Promote the i8 variants and force them on up to i32 which has a shorter // Promote the i8 variants and force them on up to i32 which has a shorter
// encoding. // encoding.
setOperationPromotedToType(ISD::CTTZ , MVT::i8 , MVT::i32); setOperationPromotedToType(ISD::CTTZ , MVT::i8 , MVT::i32);
setOperationPromotedToType(ISD::CTTZ_ZERO_UNDEF, MVT::i8 , MVT::i32); setOperationPromotedToType(ISD::CTTZ_ZERO_UNDEF, MVT::i8 , MVT::i32);
// Promote the i16 zero undef variant and force them on up to i32 when tzcnt
// is enabled.
if (Subtarget.hasBMI())
setOperationPromotedToType(ISD::CTTZ_ZERO_UNDEF, MVT::i16, MVT::i32);
if (!Subtarget.hasBMI()) { if (!Subtarget.hasBMI()) {
craig.topperUnsubmitted
Done
ReplyInline Actions

Make this an else instead of repeating the BMI check?

craig.topper: Make this an else instead of repeating the BMI check?
setOperationAction(ISD::CTTZ , MVT::i16 , Custom); setOperationAction(ISD::CTTZ , MVT::i16 , Custom);
setOperationAction(ISD::CTTZ , MVT::i32 , Custom); setOperationAction(ISD::CTTZ , MVT::i32 , Custom);
setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i16 , Legal); setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i16 , Legal);
setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i32 , Legal); setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i32 , Legal);
if (Subtarget.is64Bit()) { if (Subtarget.is64Bit()) {
setOperationAction(ISD::CTTZ , MVT::i64 , Custom); setOperationAction(ISD::CTTZ , MVT::i64 , Custom);
setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i64, Legal); setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i64, Legal);
} }
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llvm/test/CodeGen/X86/clz.ll

Show First 20 Lines • Show All 50 Lines • ▼ Show 20 Lines
; ;
; X64-LABEL: cttz_i16: ; X64-LABEL: cttz_i16:
; X64: # %bb.0: ; X64: # %bb.0:
; X64-NEXT: bsfw %di, %ax ; X64-NEXT: bsfw %di, %ax
; X64-NEXT: retq ; X64-NEXT: retq
; ;
; X86-CLZ-LABEL: cttz_i16: ; X86-CLZ-LABEL: cttz_i16:
; X86-CLZ: # %bb.0: ; X86-CLZ: # %bb.0:
; X86-CLZ-NEXT: tzcntw {{[0-9]+}}(%esp), %ax ; X86-CLZ-NEXT: tzcntl {{[0-9]+}}(%esp), %eax
; X86-CLZ-NEXT: # kill: def $ax killed $ax killed $eax
; X86-CLZ-NEXT: retl ; X86-CLZ-NEXT: retl
; ;
; X64-CLZ-LABEL: cttz_i16: ; X64-CLZ-LABEL: cttz_i16:
; X64-CLZ: # %bb.0: ; X64-CLZ: # %bb.0:
; X64-CLZ-NEXT: tzcntw %di, %ax ; X64-CLZ-NEXT: tzcntl %edi, %eax
; X64-CLZ-NEXT: # kill: def $ax killed $ax killed $eax
; X64-CLZ-NEXT: retq ; X64-CLZ-NEXT: retq
%tmp = call i16 @llvm.cttz.i16( i16 %x, i1 true ) %tmp = call i16 @llvm.cttz.i16( i16 %x, i1 true )
ret i16 %tmp ret i16 %tmp
} }
define i32 @cttz_i32(i32 %x) { define i32 @cttz_i32(i32 %x) {
; X86-LABEL: cttz_i32: ; X86-LABEL: cttz_i32:
; X86: # %bb.0: ; X86: # %bb.0:
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