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[ConstraintElimination] Decompose bitwise and or #126158

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[ConstraintElimination] Decompose bitwise and or #126158

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f000937
Add bitwise or and bitwise and decomposition tests
leewei05 Feb 4, 2025
4cf9610
Apply constraints
leewei05 Feb 6, 2025
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12 changes: 12 additions & 0 deletions llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -562,6 +562,18 @@ static Decomposition decompose(Value *V,
}
}

// (x | y) < 0 => (x < 0) || (y < 0)
if (match(V, m_Or(m_Value(Op0), m_Value(Op1)))) {
if (!isKnownNonNegative(Op0, DL) || !isKnownNonNegative(Op1, DL))
return MergeResults(Op0, Op1, IsSigned);
}

// (x & y) < 0 => (x < 0) && (y < 0)
if (match(V, m_And(m_Value(Op0), m_Value(Op1)))) {
if (!isKnownNonNegative(Op0, DL) && !isKnownNonNegative(Op1, DL))
return MergeResults(Op0, Op1, IsSigned);
}

return {V, IsKnownNonNegative};
}

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88 changes: 88 additions & 0 deletions llvm/test/Transforms/ConstraintElimination/and.ll
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Expand Up @@ -603,3 +603,91 @@ exit:

ret i1 %r.10
}

define void @test_decompose_bitwise_and(i4 %x, i4 %y) {
; CHECK-LABEL: @test_decompose_bitwise_and(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[TMP0:%.*]] = and i4 [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT: [[AND:%.*]] = icmp slt i4 [[TMP0]], 0
; CHECK-NEXT: br i1 [[AND]], label [[BB1:%.*]], label [[EXIT:%.*]]
; CHECK: bb1:
; CHECK-NEXT: [[F_1:%.*]] = icmp sge i4 [[X]], 0
; CHECK-NEXT: [[F_2:%.*]] = icmp sge i4 [[Y]], 0
; CHECK-NEXT: [[F_AND:%.*]] = and i1 false, [[F_2]]
; CHECK-NEXT: call void @use(i1 [[F_AND]])
; CHECK-NEXT: ret void
; CHECK: exit:
; CHECK-NEXT: [[F_3:%.*]] = icmp slt i4 [[X]], 0
; CHECK-NEXT: [[F_4:%.*]] = icmp slt i4 [[Y]], 0
; CHECK-NEXT: [[F_AND_2:%.*]] = and i1 false, [[F_4]]
; CHECK-NEXT: call void @use(i1 [[F_AND_2]])
; CHECK-NEXT: ret void
;
entry:
%1 = and i4 %y, %x
%and = icmp slt i4 %1, 0
br i1 %and, label %bb1, label %exit

bb1:
%f.1 = icmp sge i4 %x, 0
%f.2 = icmp sge i4 %y, 0
%f.and = and i1 %f.1, %f.2
call void @use(i1 %f.and)
ret void

exit:
%f.3 = icmp slt i4 %x, 0
%f.4 = icmp slt i4 %y, 0
%f.and.2 = and i1 %f.3, %f.4
call void @use(i1 %f.and.2)
ret void
}

define void @test_decompose_nested_bitwise_and(i4 %x, i4 %y, i4 %z) {
; CHECK-LABEL: @test_decompose_nested_bitwise_and(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[TMP0:%.*]] = and i4 [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT: [[TMP1:%.*]] = and i4 [[TMP0]], [[Z:%.*]]
; CHECK-NEXT: [[AND:%.*]] = icmp slt i4 [[TMP1]], 0
; CHECK-NEXT: br i1 [[AND]], label [[BB1:%.*]], label [[EXIT:%.*]]
; CHECK: bb1:
; CHECK-NEXT: [[F_1:%.*]] = icmp sge i4 [[X]], 0
; CHECK-NEXT: [[F_2:%.*]] = icmp sge i4 [[Y]], 0
; CHECK-NEXT: [[F_3:%.*]] = icmp sge i4 [[Z]], 0
; CHECK-NEXT: [[F_AND:%.*]] = and i1 [[F_1]], [[F_2]]
; CHECK-NEXT: [[F_AND_2:%.*]] = and i1 [[F_AND]], false
; CHECK-NEXT: call void @use(i1 [[F_AND]])
; CHECK-NEXT: ret void
; CHECK: exit:
; CHECK-NEXT: [[F_4:%.*]] = icmp slt i4 [[X]], 0
; CHECK-NEXT: [[F_5:%.*]] = icmp slt i4 [[Y]], 0
; CHECK-NEXT: [[F_6:%.*]] = icmp slt i4 [[Z]], 0
; CHECK-NEXT: [[F_AND_3:%.*]] = and i1 [[F_4]], [[F_5]]
; CHECK-NEXT: [[F_AND_4:%.*]] = and i1 [[F_AND_3]], false
; CHECK-NEXT: call void @use(i1 [[F_AND_4]])
; CHECK-NEXT: ret void
;
entry:
%1 = and i4 %y, %x
%2 = and i4 %1, %z
%and = icmp slt i4 %2, 0
br i1 %and, label %bb1, label %exit

bb1:
%f.1 = icmp sge i4 %x, 0
%f.2 = icmp sge i4 %y, 0
%f.3 = icmp sge i4 %z, 0
%f.and = and i1 %f.1, %f.2
%f.and.2 = and i1 %f.and, %f.3
call void @use(i1 %f.and)
ret void

exit:
%f.4 = icmp slt i4 %x, 0
%f.5 = icmp slt i4 %y, 0
%f.6 = icmp slt i4 %z, 0
%f.and.3 = and i1 %f.4, %f.5
%f.and.4 = and i1 %f.and.3, %f.6
call void @use(i1 %f.and.4)
ret void
}
88 changes: 88 additions & 0 deletions llvm/test/Transforms/ConstraintElimination/or.ll
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Expand Up @@ -808,3 +808,91 @@ end: ; preds = %entry

ret void
}

define void @test_decompose_bitwise_or(i4 %x, i4 %y) {
; CHECK-LABEL: @test_decompose_bitwise_or(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[TMP0:%.*]] = or i4 [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT: [[OR:%.*]] = icmp slt i4 [[TMP0]], 0
; CHECK-NEXT: br i1 [[OR]], label [[BB1:%.*]], label [[EXIT:%.*]]
; CHECK: bb1:
; CHECK-NEXT: [[F_1:%.*]] = icmp slt i4 [[X]], 0
; CHECK-NEXT: [[F_2:%.*]] = icmp slt i4 [[Y]], 0
; CHECK-NEXT: [[F_OR:%.*]] = or i1 true, [[F_2]]
; CHECK-NEXT: call void @use(i1 [[F_OR]])
; CHECK-NEXT: ret void
; CHECK: exit:
; CHECK-NEXT: [[F_3:%.*]] = icmp sge i4 [[X]], 0
; CHECK-NEXT: [[F_4:%.*]] = icmp sge i4 [[Y]], 0
; CHECK-NEXT: [[F_OR_2:%.*]] = or i1 true, [[F_4]]
; CHECK-NEXT: call void @use(i1 [[F_OR_2]])
; CHECK-NEXT: ret void
;
entry:
%1 = or i4 %y, %x
%or = icmp slt i4 %1, 0
br i1 %or, label %bb1, label %exit

bb1:
%f.1 = icmp slt i4 %x, 0
%f.2 = icmp slt i4 %y, 0
%f.or = or i1 %f.1, %f.2
call void @use(i1 %f.or)
ret void

exit:
%f.3 = icmp sge i4 %x, 0
%f.4 = icmp sge i4 %y, 0
%f.or.2 = or i1 %f.3, %f.4
call void @use(i1 %f.or.2)
ret void
}

define void @test_decompose_nested_bitwise_or(i4 %x, i4 %y, i4 %z) {
; CHECK-LABEL: @test_decompose_nested_bitwise_or(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[TMP0:%.*]] = or i4 [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT: [[TMP1:%.*]] = or i4 [[TMP0]], [[Z:%.*]]
; CHECK-NEXT: [[OR:%.*]] = icmp slt i4 [[TMP1]], 0
; CHECK-NEXT: br i1 [[OR]], label [[BB1:%.*]], label [[EXIT:%.*]]
; CHECK: bb1:
; CHECK-NEXT: [[F_1:%.*]] = icmp slt i4 [[X]], 0
; CHECK-NEXT: [[F_2:%.*]] = icmp slt i4 [[Y]], 0
; CHECK-NEXT: [[F_3:%.*]] = icmp slt i4 [[Z]], 0
; CHECK-NEXT: [[F_OR:%.*]] = or i1 [[F_1]], [[F_2]]
; CHECK-NEXT: [[F_OR_2:%.*]] = or i1 [[F_OR]], true
; CHECK-NEXT: call void @use(i1 [[F_OR_2]])
; CHECK-NEXT: ret void
; CHECK: exit:
; CHECK-NEXT: [[F_4:%.*]] = icmp sge i4 [[X]], 0
; CHECK-NEXT: [[F_5:%.*]] = icmp sge i4 [[Y]], 0
; CHECK-NEXT: [[F_6:%.*]] = icmp sge i4 [[Z]], 0
; CHECK-NEXT: [[F_OR_3:%.*]] = or i1 [[F_4]], [[F_5]]
; CHECK-NEXT: [[F_OR_4:%.*]] = or i1 [[F_OR_3]], true
; CHECK-NEXT: call void @use(i1 [[F_OR_4]])
; CHECK-NEXT: ret void
;
entry:
%1 = or i4 %y, %x
%2 = or i4 %1, %z
%or = icmp slt i4 %2, 0
br i1 %or, label %bb1, label %exit

bb1:
%f.1 = icmp slt i4 %x, 0
%f.2 = icmp slt i4 %y, 0
%f.3 = icmp slt i4 %z, 0
%f.or = or i1 %f.1, %f.2
%f.or.2 = or i1 %f.or, %f.3
call void @use(i1 %f.or.2)
ret void

exit:
%f.4 = icmp sge i4 %x, 0
%f.5 = icmp sge i4 %y, 0
%f.6 = icmp sge i4 %z, 0
%f.or.3 = or i1 %f.4, %f.5
%f.or.4 = or i1 %f.or.3, %f.6
call void @use(i1 %f.or.4)
ret void
}