[llvm] f82c55f - [InstCombine] Change order of canonicalization of ADD and AND
Jay Foad via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 22 12:04:07 PDT 2022
Author: Jay Foad
Date: 2022-08-22T20:03:53+01:00
New Revision: f82c55fa082711f520a7359393b483956b69bf08
URL: https://github.com/llvm/llvm-project/commit/f82c55fa082711f520a7359393b483956b69bf08
DIFF: https://github.com/llvm/llvm-project/commit/f82c55fa082711f520a7359393b483956b69bf08.diff
LOG: [InstCombine] Change order of canonicalization of ADD and AND
Canonicalize ((x + C1) & C2) --> ((x & C2) + C1) for suitable constants
C1 and C2, instead of the other way round. This should allow more
constant ADDs to be matched as part of addressing modes for loads and
stores.
Differential Revision: https://reviews.llvm.org/D130080
Added:
Modified:
llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
llvm/test/Transforms/InstCombine/add.ll
llvm/test/Transforms/InstCombine/integer-round-up-pow2-alignment.ll
llvm/test/Transforms/InstCombine/or.ll
llvm/test/Transforms/InstCombine/sub.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index 528c74a2e3308..94f21dd3c6ccd 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -969,15 +969,6 @@ Instruction *InstCombinerImpl::foldAddWithConstant(BinaryOperator &Add) {
}
}
- // If all bits affected by the add are included in a high-bit-mask, do the
- // add before the mask op:
- // (X & 0xFF00) + xx00 --> (X + xx00) & 0xFF00
- if (match(Op0, m_OneUse(m_And(m_Value(X), m_APInt(C2)))) &&
- C2->isNegative() && C2->isShiftedMask() && *C == (*C & *C2)) {
- Value *NewAdd = Builder.CreateAdd(X, ConstantInt::get(Ty, *C));
- return BinaryOperator::CreateAnd(NewAdd, ConstantInt::get(Ty, *C2));
- }
-
return nullptr;
}
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 59217d9db3d48..321cf6519787d 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1888,6 +1888,14 @@ Instruction *InstCombinerImpl::visitAnd(BinaryOperator &I) {
Value *NewAnd = Builder.CreateAnd(X, Op1);
return BinaryOperator::CreateXor(NewAnd, Op1);
}
+
+ // If all bits affected by the add are included in a high-bit-mask, do the
+ // mask op before the add. Example:
+ // (X + 16) & -4 --> (X & -4) + 16
+ if (Op0->hasOneUse() && C->isNegatedPowerOf2() && *AddC == (*AddC & *C)) {
+ Value *NewAnd = Builder.CreateAnd(X, Op1);
+ return BinaryOperator::CreateAdd(NewAnd, ConstantInt::get(Ty, *AddC));
+ }
}
// ((C1 OP zext(X)) & C2) -> zext((C1 OP X) & C2) if C2 fits in the
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index f6f8f1141df43..98cf450a95268 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -2602,10 +2602,14 @@ foldRoundUpIntegerWithPow2Alignment(SelectInst &SI,
if (!match(XLowBits, m_And(m_Specific(X), m_APIntAllowUndef(LowBitMaskCst))))
return nullptr;
+ // Match even if the AND and ADD are swapped.
const APInt *BiasCst, *HighBitMaskCst;
if (!match(XBiasedHighBits,
m_And(m_Add(m_Specific(X), m_APIntAllowUndef(BiasCst)),
- m_APIntAllowUndef(HighBitMaskCst))))
+ m_APIntAllowUndef(HighBitMaskCst))) &&
+ !match(XBiasedHighBits,
+ m_Add(m_And(m_Specific(X), m_APIntAllowUndef(HighBitMaskCst)),
+ m_APIntAllowUndef(BiasCst))))
return nullptr;
if (!LowBitMaskCst->isMask())
diff --git a/llvm/test/Transforms/InstCombine/add.ll b/llvm/test/Transforms/InstCombine/add.ll
index 86f65e5135379..0df79e4be3e4c 100644
--- a/llvm/test/Transforms/InstCombine/add.ll
+++ b/llvm/test/Transforms/InstCombine/add.ll
@@ -724,12 +724,12 @@ define i8 @test34(i8 %A) {
}
; If all bits affected by the add are included
-; in the mask, do the add before the mask op.
+; in the mask, do the mask op before the add.
define i8 @masked_add(i8 %x) {
; CHECK-LABEL: @masked_add(
-; CHECK-NEXT: [[TMP1:%.*]] = add i8 [[X:%.*]], 96
-; CHECK-NEXT: [[R:%.*]] = and i8 [[TMP1]], -16
+; CHECK-NEXT: [[AND:%.*]] = and i8 [[X:%.*]], -16
+; CHECK-NEXT: [[R:%.*]] = add i8 [[AND]], 96
; CHECK-NEXT: ret i8 [[R]]
;
%and = and i8 %x, 240 ; 0xf0
@@ -739,8 +739,8 @@ define i8 @masked_add(i8 %x) {
define <2 x i8> @masked_add_splat(<2 x i8> %x) {
; CHECK-LABEL: @masked_add_splat(
-; CHECK-NEXT: [[TMP1:%.*]] = add <2 x i8> [[X:%.*]], <i8 64, i8 64>
-; CHECK-NEXT: [[R:%.*]] = and <2 x i8> [[TMP1]], <i8 -64, i8 -64>
+; CHECK-NEXT: [[AND:%.*]] = and <2 x i8> [[X:%.*]], <i8 -64, i8 -64>
+; CHECK-NEXT: [[R:%.*]] = add <2 x i8> [[AND]], <i8 64, i8 64>
; CHECK-NEXT: ret <2 x i8> [[R]]
;
%and = and <2 x i8> %x, <i8 192, i8 192> ; 0xc0
@@ -761,14 +761,14 @@ define i8 @not_masked_add(i8 %x) {
define i8 @masked_add_multi_use(i8 %x) {
; CHECK-LABEL: @masked_add_multi_use(
-; CHECK-NEXT: [[TMP:%.*]] = add i8 [[X:%.*]], 96
-; CHECK-NEXT: [[R:%.*]] = and i8 [[TMP:%.*]], -16
-; CHECK-NEXT: call void @use(i8 [[X]])
+; CHECK-NEXT: [[AND:%.*]] = and i8 [[X:%.*]], -16
+; CHECK-NEXT: [[R:%.*]] = add i8 [[AND]], 96
+; CHECK-NEXT: call void @use(i8 [[AND]])
; CHECK-NEXT: ret i8 [[R]]
;
%and = and i8 %x, -16 ; 0xf0
%r = add i8 %and, 96 ; 0x60
- call void @use(i8 %x) ; extra use
+ call void @use(i8 %and) ; extra use
ret i8 %r
}
diff --git a/llvm/test/Transforms/InstCombine/integer-round-up-pow2-alignment.ll b/llvm/test/Transforms/InstCombine/integer-round-up-pow2-alignment.ll
index 58dbf1409bfb4..04f8d2c2a2e7a 100644
--- a/llvm/test/Transforms/InstCombine/integer-round-up-pow2-alignment.ll
+++ b/llvm/test/Transforms/InstCombine/integer-round-up-pow2-alignment.ll
@@ -247,8 +247,8 @@ define i8 @n9_wrong_x0(i8 %x.0, i8 %x.1) {
; CHECK-LABEL: @n9_wrong_x0(
; CHECK-NEXT: [[X_LOWBITS:%.*]] = and i8 [[X_0:%.*]], 15
; CHECK-NEXT: [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
-; CHECK-NEXT: [[X_BIASED:%.*]] = add i8 [[X_0]], 16
-; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = and i8 [[X_BIASED]], -16
+; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X_0]], -16
+; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT: [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X_1:%.*]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT: ret i8 [[X_ROUNDEDUP]]
;
@@ -263,8 +263,8 @@ define i8 @n9_wrong_x1(i8 %x.0, i8 %x.1) {
; CHECK-LABEL: @n9_wrong_x1(
; CHECK-NEXT: [[X_LOWBITS:%.*]] = and i8 [[X_0:%.*]], 15
; CHECK-NEXT: [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
-; CHECK-NEXT: [[X_BIASED:%.*]] = add i8 [[X_1:%.*]], 16
-; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = and i8 [[X_BIASED]], -16
+; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X_1:%.*]], -16
+; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT: [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X_0]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT: ret i8 [[X_ROUNDEDUP]]
;
@@ -279,8 +279,8 @@ define i8 @n9_wrong_x2(i8 %x.0, i8 %x.1) {
; CHECK-LABEL: @n9_wrong_x2(
; CHECK-NEXT: [[X_LOWBITS:%.*]] = and i8 [[X_1:%.*]], 15
; CHECK-NEXT: [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
-; CHECK-NEXT: [[X_BIASED:%.*]] = add i8 [[X_0:%.*]], 16
-; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = and i8 [[X_BIASED]], -16
+; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X_0:%.*]], -16
+; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT: [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X_0]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT: ret i8 [[X_ROUNDEDUP]]
;
@@ -297,8 +297,8 @@ define i8 @n10_wrong_low_bit_mask(i8 %x) {
; CHECK-LABEL: @n10_wrong_low_bit_mask(
; CHECK-NEXT: [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 31
; CHECK-NEXT: [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
-; CHECK-NEXT: [[X_BIASED:%.*]] = add i8 [[X]], 16
-; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = and i8 [[X_BIASED]], -16
+; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X]], -16
+; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT: [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT: ret i8 [[X_ROUNDEDUP]]
;
@@ -333,8 +333,8 @@ define i8 @n12_wrong_bias(i8 %x) {
; CHECK-LABEL: @n12_wrong_bias(
; CHECK-NEXT: [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 15
; CHECK-NEXT: [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
-; CHECK-NEXT: [[X_BIASED:%.*]] = add i8 [[X]], 32
-; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = and i8 [[X_BIASED]], -16
+; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X]], -16
+; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 32
; CHECK-NEXT: [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT: ret i8 [[X_ROUNDEDUP]]
;
@@ -369,8 +369,8 @@ define i8 @n14_wrong_comparison_constant(i8 %x) {
; CHECK-LABEL: @n14_wrong_comparison_constant(
; CHECK-NEXT: [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 15
; CHECK-NEXT: [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 1
-; CHECK-NEXT: [[X_BIASED:%.*]] = add i8 [[X]], 16
-; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = and i8 [[X_BIASED]], -16
+; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X]], -16
+; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT: [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT: ret i8 [[X_ROUNDEDUP]]
;
@@ -387,8 +387,8 @@ define i8 @n15_wrong_comparison_predicate_and_constant(i8 %x) {
; CHECK-LABEL: @n15_wrong_comparison_predicate_and_constant(
; CHECK-NEXT: [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 14
; CHECK-NEXT: [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
-; CHECK-NEXT: [[X_BIASED:%.*]] = add i8 [[X]], 16
-; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = and i8 [[X_BIASED]], -16
+; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X]], -16
+; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT: [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT: ret i8 [[X_ROUNDEDUP]]
;
@@ -405,8 +405,8 @@ define i8 @n16_oneuse(i8 %x) {
; CHECK-LABEL: @n16_oneuse(
; CHECK-NEXT: [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 15
; CHECK-NEXT: [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
-; CHECK-NEXT: [[X_BIASED:%.*]] = add i8 [[X]], 16
-; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = and i8 [[X_BIASED]], -16
+; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X]], -16
+; CHECK-NEXT: [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT: call void @use.i8(i8 [[X_BIASED_HIGHBITS]])
; CHECK-NEXT: [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT: ret i8 [[X_ROUNDEDUP]]
diff --git a/llvm/test/Transforms/InstCombine/or.ll b/llvm/test/Transforms/InstCombine/or.ll
index eb7c3a48ae809..7dacb1877c27b 100644
--- a/llvm/test/Transforms/InstCombine/or.ll
+++ b/llvm/test/Transforms/InstCombine/or.ll
@@ -154,10 +154,14 @@ define i32 @test20(i32 %x) {
ret i32 %z
}
+; TODO: This should combine to t1 + 2.
define i32 @test21(i32 %t1) {
; CHECK-LABEL: @test21(
-; CHECK-NEXT: [[T1_MASK1:%.*]] = add i32 [[T1:%.*]], 2
-; CHECK-NEXT: ret i32 [[T1_MASK1]]
+; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[T1:%.*]], -2
+; CHECK-NEXT: [[T3:%.*]] = add i32 [[TMP1]], 2
+; CHECK-NEXT: [[T5:%.*]] = and i32 [[T1]], 1
+; CHECK-NEXT: [[T6:%.*]] = or i32 [[T5]], [[T3]]
+; CHECK-NEXT: ret i32 [[T6]]
;
%t1.mask1 = add i32 %t1, 2
%t3 = and i32 %t1.mask1, -2
diff --git a/llvm/test/Transforms/InstCombine/sub.ll b/llvm/test/Transforms/InstCombine/sub.ll
index f7d99a0841760..fa243dffb1ccb 100644
--- a/llvm/test/Transforms/InstCombine/sub.ll
+++ b/llvm/test/Transforms/InstCombine/sub.ll
@@ -1490,8 +1490,8 @@ define i8 @sub_add_sub_reassoc_use2(i8 %w, i8 %x, i8 %y, i8 %z) {
define i8 @sub_mask_lowbits(i8 %x) {
; CHECK-LABEL: @sub_mask_lowbits(
-; CHECK-NEXT: [[A1:%.*]] = add i8 [[X:%.*]], -108
-; CHECK-NEXT: [[R:%.*]] = and i8 [[A1]], -4
+; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X:%.*]], -4
+; CHECK-NEXT: [[R:%.*]] = add i8 [[TMP1]], -108
; CHECK-NEXT: ret i8 [[R]]
;
%a1 = add i8 %x, 148 ; 0x94
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