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Differential D91725

[LoopIdiom] 'left-shift until bittest' idiom: support constant bit mask
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Authored by lebedev.ri on Nov 18 2020, 10:28 AM.

Details

Reviewers
craig.topper
fhahn
jdoerfert
Commits
rGcb2e5980bae3: [LoopIdiom] 'left-shift until bittest' idiom: support constant bit mask
Summary

The handing of the case where the mask is a constant is trivial,
if said constant is a power of two, the bit in question is log2(mask),
rest just works.

Diff Detail

Event Timeline

lebedev.ri created this revision.Nov 18 2020, 10:28 AM
Herald added a subscriber: hiraditya. · View Herald TranscriptNov 18 2020, 10:28 AM
lebedev.ri requested review of this revision.Nov 18 2020, 10:28 AM
lebedev.ri added a child revision: D91726: [LoopIdiom] 'left-shift until bittest' idiom: support canonical sign bit mask.
Harbormaster completed remote builds in B79323: Diff 306148.Nov 18 2020, 10:29 AM
lebedev.ri updated this revision to Diff 306166.Nov 18 2020, 11:18 AM

Do recurrence analysis afterwards, not when matching backedge condition.

Harbormaster completed remote builds in B79331: Diff 306166.Nov 18 2020, 11:18 AM
lebedev.ri added a parent revision: D91038: [LoopIdiom] Introduce 'left-shift until bittest' idiom.Dec 7 2020, 4:29 AM
lebedev.ri updated this revision to Diff 309875.Dec 7 2020, 4:40 AM

Rebased, NFC.

Harbormaster completed remote builds in B81276: Diff 309875.Dec 7 2020, 6:00 AM
lebedev.ri updated this revision to Diff 311685.Dec 14 2020, 1:27 PM

Rebased, NFC.

Harbormaster completed remote builds in B82327: Diff 311685.Dec 14 2020, 2:07 PM
lebedev.ri updated this revision to Diff 311818.Dec 15 2020, 12:31 AM

Rebased, NFC.

Harbormaster completed remote builds in B82413: Diff 311818.Dec 15 2020, 12:33 AM
lebedev.ri mentioned this in D91038: [LoopIdiom] Introduce 'left-shift until bittest' idiom.Dec 18 2020, 1:09 PM
craig.topper accepted this revision.Dec 23 2020, 9:39 AM

LGTM

This revision is now accepted and ready to land.Dec 23 2020, 9:39 AM
lebedev.ri added a comment.Dec 23 2020, 9:59 AM
In D91725#2470186, @craig.topper wrote:

LGTM

Thank you for the review!

lebedev.ri updated this revision to Diff 313578.Dec 23 2020, 11:25 AM

Rebased, NFC.

This revision was landed with ongoing or failed builds.Dec 23 2020, 11:28 AM
Closed by commit rGcb2e5980bae3: [LoopIdiom] 'left-shift until bittest' idiom: support constant bit mask (authored by lebedev.ri). · Explain Why
This revision was automatically updated to reflect the committed changes.
lebedev.ri added a commit: rGcb2e5980bae3: [LoopIdiom] 'left-shift until bittest' idiom: support constant bit mask.
Harbormaster completed remote builds in B83412: Diff 313578.Dec 23 2020, 12:34 PM

Revision Contents

PathSize
llvm/
lib/
Transforms/
Scalar/
9 lines
test/
Transforms/
LoopIdiom/
X86/
173 lines

Diff 306166

llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp

Show First 20 Lines • Show All 2,039 Lines • ▼ Show 20 Lines auto MatchVariableBitMask = [&]() {
return ICmpInst::isEquality(Pred) && match(CmpRHS, m_Zero()) && return ICmpInst::isEquality(Pred) && match(CmpRHS, m_Zero()) &&
match(CmpLHS, match(CmpLHS,
m_c_And(m_Value(Rec), m_c_And(m_Value(Rec),
m_CombineAnd( m_CombineAnd(
m_Value(BitMask), m_Value(BitMask),
m_LoopInvariant(m_Shl(m_One(), m_Value(BitPos)), m_LoopInvariant(m_Shl(m_One(), m_Value(BitPos)),
CurLoop)))); CurLoop))));
}; };
auto MatchConstantBitMask = [&]() {
return ICmpInst::isEquality(Pred) && match(CmpRHS, m_Zero()) &&
match(CmpLHS, m_c_And(m_Value(Rec),
m_CombineAnd(m_Value(BitMask), m_Power2()))) &&
(BitPos = ConstantExpr::getExactLogBase2(cast<Constant>(BitMask)));
};
if (!MatchVariableBitMask()) { if (!MatchVariableBitMask() && !MatchConstantBitMask()) {
// FIXME: support constant bit mask.
// FIXME: support sign bit test (use llvm::decomposeBitTestICmp()). // FIXME: support sign bit test (use llvm::decomposeBitTestICmp()).
LLVM_DEBUG(dbgs() << DEBUG_TYPE " Bad backedge comparison.\n"); LLVM_DEBUG(dbgs() << DEBUG_TYPE " Bad backedge comparison.\n");
return false; return false;
} }
// Step 3: Check if the recurrence is in desirable form. // Step 3: Check if the recurrence is in desirable form.
if (!match(Rec, m_CombineAnd( if (!match(Rec, m_CombineAnd(
m_Value(CurrX), m_Value(CurrX),
▲ Show 20 Lines • Show All 178 Lines • Show Last 20 Lines

llvm/test/Transforms/LoopIdiom/X86/left-shift-until-bittest.ll

Show First 20 Lines • Show All 138 Lines • ▼ Show 20 Linesloop:
%x.next = shl i16 %x.curr, 1 %x.next = shl i16 %x.curr, 1
br i1 %x.curr.isbitunset, label %loop, label %end br i1 %x.curr.isbitunset, label %loop, label %end
end: end:
ret i16 %x.curr ret i16 %x.curr
} }
define i32 @p2_constant_mask_24thbit(i32 %x) { define i32 @p2_constant_mask_24thbit(i32 %x) {
; ALL-LABEL: @p2_constant_mask_24thbit( ; LZCNT-LABEL: @p2_constant_mask_24thbit(
; ALL-NEXT: entry: ; LZCNT-NEXT: entry:
; ALL-NEXT: br label [[LOOP:%.*]], [[DBG46:!dbg !.*]] ; LZCNT-NEXT: [[X_MASKED:%.*]] = and i32 [[X:%.*]], 33554431, [[DBG46:!dbg !.*]]
; ALL: loop: ; LZCNT-NEXT: [[X_MASKED_NUMLEADINGZEROS:%.*]] = call i32 @llvm.ctlz.i32(i32 [[X_MASKED]], i1 true), [[DBG46]]
; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG47:!dbg !.*]] ; LZCNT-NEXT: [[X_MASKED_NUMACTIVEBITS:%.*]] = sub i32 32, [[X_MASKED_NUMLEADINGZEROS]], [[DBG46]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META42:metadata !.*]], metadata !DIExpression()), [[DBG47]] ; LZCNT-NEXT: [[X_MASKED_NUMLEADINGONEPOS:%.*]] = add i32 [[X_MASKED_NUMACTIVEBITS]], -1, [[DBG46]]
; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], 16777216, [[DBG48:!dbg !.*]] ; LZCNT-NEXT: [[X_MASKED_LOOPTRIPCOUNT:%.*]] = sub i32 24, [[X_MASKED_NUMLEADINGONEPOS]], [[DBG46]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META43:metadata !.*]], metadata !DIExpression()), [[DBG48]] ; LZCNT-NEXT: [[X_CURR:%.*]] = shl i32 [[X]], [[X_MASKED_LOOPTRIPCOUNT]], [[DBG46]]
; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG49:!dbg !.*]] ; LZCNT-NEXT: br label [[LOOP:%.*]], [[DBG47:!dbg !.*]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META44:metadata !.*]], metadata !DIExpression()), [[DBG49]] ; LZCNT: loop:
; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG50:!dbg !.*]] ; LZCNT-NEXT: [[TMP0:%.*]] = phi i32 [ [[X]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG46]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META45:metadata !.*]], metadata !DIExpression()), [[DBG50]] ; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META42:metadata !.*]], metadata !DIExpression()), [[DBG46]]
; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG51:!dbg !.*]] ; LZCNT-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], 16777216, [[DBG48:!dbg !.*]]
; ALL: end: ; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META43:metadata !.*]], metadata !DIExpression()), [[DBG48]]
; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG47]] ; LZCNT-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG49:!dbg !.*]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META42]], metadata !DIExpression()), [[DBG47]] ; LZCNT-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META44:metadata !.*]], metadata !DIExpression()), [[DBG49]]
; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG52:!dbg !.*]] ; LZCNT-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG50:!dbg !.*]]
; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META45:metadata !.*]], metadata !DIExpression()), [[DBG50]]
; LZCNT-NEXT: br i1 true, label [[END:%.*]], label [[LOOP]], [[DBG51:!dbg !.*]]
; LZCNT: end:
; LZCNT-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG46]]
; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META42]], metadata !DIExpression()), [[DBG46]]
; LZCNT-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG52:!dbg !.*]]
;
; NOLZCNT-LABEL: @p2_constant_mask_24thbit(
; NOLZCNT-NEXT: entry:
; NOLZCNT-NEXT: br label [[LOOP:%.*]], [[DBG46:!dbg !.*]]
; NOLZCNT: loop:
; NOLZCNT-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG47:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META42:metadata !.*]], metadata !DIExpression()), [[DBG47]]
; NOLZCNT-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], 16777216, [[DBG48:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META43:metadata !.*]], metadata !DIExpression()), [[DBG48]]
; NOLZCNT-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG49:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META44:metadata !.*]], metadata !DIExpression()), [[DBG49]]
; NOLZCNT-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG50:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META45:metadata !.*]], metadata !DIExpression()), [[DBG50]]
; NOLZCNT-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG51:!dbg !.*]]
; NOLZCNT: end:
; NOLZCNT-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG47]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META42]], metadata !DIExpression()), [[DBG47]]
; NOLZCNT-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG52:!dbg !.*]]
; ;
entry: entry:
br label %loop br label %loop
loop: loop:
%x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ] %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
%x.curr.bitmasked = and i32 %x.curr, 16777216 %x.curr.bitmasked = and i32 %x.curr, 16777216
%x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0 %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
%x.next = shl i32 %x.curr, 1 %x.next = shl i32 %x.curr, 1
br i1 %x.curr.isbitunset, label %loop, label %end br i1 %x.curr.isbitunset, label %loop, label %end
end: end:
ret i32 %x.curr ret i32 %x.curr
} }
define i32 @p3_constant_mask_15thbit(i32 %x) { define i32 @p3_constant_mask_15thbit(i32 %x) {
; ALL-LABEL: @p3_constant_mask_15thbit( ; LZCNT-LABEL: @p3_constant_mask_15thbit(
; ALL-NEXT: entry: ; LZCNT-NEXT: entry:
; ALL-NEXT: br label [[LOOP:%.*]], [[DBG59:!dbg !.*]] ; LZCNT-NEXT: [[X_MASKED:%.*]] = and i32 [[X:%.*]], 65535, [[DBG59:!dbg !.*]]
; ALL: loop: ; LZCNT-NEXT: [[X_MASKED_NUMLEADINGZEROS:%.*]] = call i32 @llvm.ctlz.i32(i32 [[X_MASKED]], i1 true), [[DBG59]]
; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG60:!dbg !.*]] ; LZCNT-NEXT: [[X_MASKED_NUMACTIVEBITS:%.*]] = sub i32 32, [[X_MASKED_NUMLEADINGZEROS]], [[DBG59]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META55:metadata !.*]], metadata !DIExpression()), [[DBG60]] ; LZCNT-NEXT: [[X_MASKED_NUMLEADINGONEPOS:%.*]] = add i32 [[X_MASKED_NUMACTIVEBITS]], -1, [[DBG59]]
; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], 32768, [[DBG61:!dbg !.*]] ; LZCNT-NEXT: [[X_MASKED_LOOPTRIPCOUNT:%.*]] = sub i32 15, [[X_MASKED_NUMLEADINGONEPOS]], [[DBG59]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META56:metadata !.*]], metadata !DIExpression()), [[DBG61]] ; LZCNT-NEXT: [[X_CURR:%.*]] = shl i32 [[X]], [[X_MASKED_LOOPTRIPCOUNT]], [[DBG59]]
; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG62:!dbg !.*]] ; LZCNT-NEXT: br label [[LOOP:%.*]], [[DBG60:!dbg !.*]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META57:metadata !.*]], metadata !DIExpression()), [[DBG62]] ; LZCNT: loop:
; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG63:!dbg !.*]] ; LZCNT-NEXT: [[TMP0:%.*]] = phi i32 [ [[X]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG59]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META58:metadata !.*]], metadata !DIExpression()), [[DBG63]] ; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META55:metadata !.*]], metadata !DIExpression()), [[DBG59]]
; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG64:!dbg !.*]] ; LZCNT-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], 32768, [[DBG61:!dbg !.*]]
; ALL: end: ; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META56:metadata !.*]], metadata !DIExpression()), [[DBG61]]
; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG60]] ; LZCNT-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG62:!dbg !.*]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META55]], metadata !DIExpression()), [[DBG60]] ; LZCNT-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META57:metadata !.*]], metadata !DIExpression()), [[DBG62]]
; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG65:!dbg !.*]] ; LZCNT-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG63:!dbg !.*]]
; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META58:metadata !.*]], metadata !DIExpression()), [[DBG63]]
; LZCNT-NEXT: br i1 true, label [[END:%.*]], label [[LOOP]], [[DBG64:!dbg !.*]]
; LZCNT: end:
; LZCNT-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG59]]
; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META55]], metadata !DIExpression()), [[DBG59]]
; LZCNT-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG65:!dbg !.*]]
;
; NOLZCNT-LABEL: @p3_constant_mask_15thbit(
; NOLZCNT-NEXT: entry:
; NOLZCNT-NEXT: br label [[LOOP:%.*]], [[DBG59:!dbg !.*]]
; NOLZCNT: loop:
; NOLZCNT-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG60:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META55:metadata !.*]], metadata !DIExpression()), [[DBG60]]
; NOLZCNT-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], 32768, [[DBG61:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META56:metadata !.*]], metadata !DIExpression()), [[DBG61]]
; NOLZCNT-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG62:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META57:metadata !.*]], metadata !DIExpression()), [[DBG62]]
; NOLZCNT-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG63:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META58:metadata !.*]], metadata !DIExpression()), [[DBG63]]
; NOLZCNT-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG64:!dbg !.*]]
; NOLZCNT: end:
; NOLZCNT-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG60]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META55]], metadata !DIExpression()), [[DBG60]]
; NOLZCNT-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG65:!dbg !.*]]
; ;
entry: entry:
br label %loop br label %loop
loop: loop:
%x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ] %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
%x.curr.bitmasked = and i32 %x.curr, 32768 %x.curr.bitmasked = and i32 %x.curr, 32768
%x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0 %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
%x.next = shl i32 %x.curr, 1 %x.next = shl i32 %x.curr, 1
br i1 %x.curr.isbitunset, label %loop, label %end br i1 %x.curr.isbitunset, label %loop, label %end
end: end:
ret i32 %x.curr ret i32 %x.curr
} }
define i32 @p4_constant_mask_signbit_noncanonical(i32 %x) { define i32 @p4_constant_mask_signbit_noncanonical(i32 %x) {
; ALL-LABEL: @p4_constant_mask_signbit_noncanonical( ; LZCNT-LABEL: @p4_constant_mask_signbit_noncanonical(
; ALL-NEXT: entry: ; LZCNT-NEXT: entry:
; ALL-NEXT: br label [[LOOP:%.*]], [[DBG72:!dbg !.*]] ; LZCNT-NEXT: [[X_NUMLEADINGZEROS:%.*]] = call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 true), [[DBG72:!dbg !.*]]
; ALL: loop: ; LZCNT-NEXT: [[X_NUMACTIVEBITS:%.*]] = sub i32 32, [[X_NUMLEADINGZEROS]], [[DBG72]]
; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG73:!dbg !.*]] ; LZCNT-NEXT: [[X_NUMLEADINGONEPOS:%.*]] = add i32 [[X_NUMACTIVEBITS]], -1, [[DBG72]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META68:metadata !.*]], metadata !DIExpression()), [[DBG73]] ; LZCNT-NEXT: [[X_LOOPTRIPCOUNT:%.*]] = sub i32 31, [[X_NUMLEADINGONEPOS]], [[DBG72]]
; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], -2147483648, [[DBG74:!dbg !.*]] ; LZCNT-NEXT: [[X_CURR:%.*]] = shl i32 [[X]], [[X_LOOPTRIPCOUNT]], [[DBG72]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META69:metadata !.*]], metadata !DIExpression()), [[DBG74]] ; LZCNT-NEXT: br label [[LOOP:%.*]], [[DBG73:!dbg !.*]]
; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG75:!dbg !.*]] ; LZCNT: loop:
; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META70:metadata !.*]], metadata !DIExpression()), [[DBG75]] ; LZCNT-NEXT: [[TMP0:%.*]] = phi i32 [ [[X]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG72]]
; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG76:!dbg !.*]] ; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META68:metadata !.*]], metadata !DIExpression()), [[DBG72]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META71:metadata !.*]], metadata !DIExpression()), [[DBG76]] ; LZCNT-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], -2147483648, [[DBG74:!dbg !.*]]
; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG77:!dbg !.*]] ; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META69:metadata !.*]], metadata !DIExpression()), [[DBG74]]
; ALL: end: ; LZCNT-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG75:!dbg !.*]]
; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG73]] ; LZCNT-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META70:metadata !.*]], metadata !DIExpression()), [[DBG75]]
; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META68]], metadata !DIExpression()), [[DBG73]] ; LZCNT-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG76:!dbg !.*]]
; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG78:!dbg !.*]] ; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META71:metadata !.*]], metadata !DIExpression()), [[DBG76]]
; LZCNT-NEXT: br i1 true, label [[END:%.*]], label [[LOOP]], [[DBG77:!dbg !.*]]
; LZCNT: end:
; LZCNT-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG72]]
; LZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META68]], metadata !DIExpression()), [[DBG72]]
; LZCNT-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG78:!dbg !.*]]
;
; NOLZCNT-LABEL: @p4_constant_mask_signbit_noncanonical(
; NOLZCNT-NEXT: entry:
; NOLZCNT-NEXT: br label [[LOOP:%.*]], [[DBG72:!dbg !.*]]
; NOLZCNT: loop:
; NOLZCNT-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG73:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META68:metadata !.*]], metadata !DIExpression()), [[DBG73]]
; NOLZCNT-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], -2147483648, [[DBG74:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META69:metadata !.*]], metadata !DIExpression()), [[DBG74]]
; NOLZCNT-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG75:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META70:metadata !.*]], metadata !DIExpression()), [[DBG75]]
; NOLZCNT-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG76:!dbg !.*]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META71:metadata !.*]], metadata !DIExpression()), [[DBG76]]
; NOLZCNT-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG77:!dbg !.*]]
; NOLZCNT: end:
; NOLZCNT-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG73]]
; NOLZCNT-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META68]], metadata !DIExpression()), [[DBG73]]
; NOLZCNT-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG78:!dbg !.*]]
; ;
entry: entry:
br label %loop br label %loop
loop: loop:
%x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ] %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
%x.curr.bitmasked = and i32 %x.curr, 2147483648 %x.curr.bitmasked = and i32 %x.curr, 2147483648
%x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0 %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
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