[llvm] ee50925 - [InstCombine] Fold (X != 0) & (Y u>= X)
Nikita Popov via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 25 04:16:55 PDT 2022
Author: Nikita Popov
Date: 2022-04-25T13:16:47+02:00
New Revision: ee509258947cc07c899a0b5ad6fffdefd27f958f
URL: https://github.com/llvm/llvm-project/commit/ee509258947cc07c899a0b5ad6fffdefd27f958f
DIFF: https://github.com/llvm/llvm-project/commit/ee509258947cc07c899a0b5ad6fffdefd27f958f.diff
LOG: [InstCombine] Fold (X != 0) & (Y u>= X)
This adds the De Morgan conjugated fold for the existing
(X == 0) | (Y u< X) fold.
Proof: https://alive2.llvm.org/ce/z/3Me3JQ
Added:
Modified:
llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
llvm/test/Transforms/InstCombine/icmp.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 2ef03ad4044ed..4a97d6b83767b 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -2382,13 +2382,13 @@ Value *InstCombinerImpl::matchSelectFromAndOr(Value *A, Value *C, Value *B,
}
// (icmp eq X, 0) | (icmp ult Other, X) -> (icmp ule Other, X-1)
+// (icmp ne X, 0) & (icmp uge Other, X) -> (icmp ugt Other, X-1)
Value *foldAndOrOfICmpEqZeroAndICmp(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
IRBuilderBase &Builder) {
- if (IsAnd)
- return nullptr;
-
- ICmpInst::Predicate LPred = LHS->getPredicate();
- ICmpInst::Predicate RPred = RHS->getPredicate();
+ ICmpInst::Predicate LPred =
+ IsAnd ? LHS->getInversePredicate() : LHS->getPredicate();
+ ICmpInst::Predicate RPred =
+ IsAnd ? RHS->getInversePredicate() : RHS->getPredicate();
Value *LHS0 = LHS->getOperand(0);
if (LPred != ICmpInst::ICMP_EQ || !match(LHS->getOperand(1), m_Zero()) ||
!LHS0->getType()->isIntOrIntVectorTy() ||
@@ -2404,7 +2404,7 @@ Value *foldAndOrOfICmpEqZeroAndICmp(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
return nullptr;
return Builder.CreateICmp(
- ICmpInst::ICMP_UGE,
+ IsAnd ? ICmpInst::ICMP_ULT : ICmpInst::ICMP_UGE,
Builder.CreateAdd(LHS0, Constant::getAllOnesValue(LHS0->getType())),
Other);
}
diff --git a/llvm/test/Transforms/InstCombine/icmp.ll b/llvm/test/Transforms/InstCombine/icmp.ll
index 24945c783c7ae..b8dc9fba3195f 100644
--- a/llvm/test/Transforms/InstCombine/icmp.ll
+++ b/llvm/test/Transforms/InstCombine/icmp.ll
@@ -2258,10 +2258,9 @@ define <2 x i1> @or_icmp_ne_A_0_icmp_ne_B_0_undef(<2 x i64> %a, <2 x i64> %b) {
define i1 @and_icmp_ne_B_0_icmp_uge_A_B(i64 %a, i64 %b) {
; CHECK-LABEL: @and_icmp_ne_B_0_icmp_uge_A_B(
-; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i64 [[B:%.*]], 0
-; CHECK-NEXT: [[TMP2:%.*]] = icmp uge i64 [[A:%.*]], [[B]]
-; CHECK-NEXT: [[TMP3:%.*]] = and i1 [[TMP1]], [[TMP2]]
-; CHECK-NEXT: ret i1 [[TMP3]]
+; CHECK-NEXT: [[TMP1:%.*]] = add i64 [[B:%.*]], -1
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i64 [[TMP1]], [[A:%.*]]
+; CHECK-NEXT: ret i1 [[TMP2]]
;
%1 = icmp ne i64 %b, 0
%2 = icmp uge i64 %a, %b
@@ -2271,10 +2270,9 @@ define i1 @and_icmp_ne_B_0_icmp_uge_A_B(i64 %a, i64 %b) {
define i1 @and_icmp_ne_B_0_icmp_uge_A_B_commuted1(i64 %a, i64 %b) {
; CHECK-LABEL: @and_icmp_ne_B_0_icmp_uge_A_B_commuted1(
-; CHECK-NEXT: [[TMP1:%.*]] = icmp uge i64 [[A:%.*]], [[B:%.*]]
-; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i64 [[B]], 0
-; CHECK-NEXT: [[TMP3:%.*]] = and i1 [[TMP1]], [[TMP2]]
-; CHECK-NEXT: ret i1 [[TMP3]]
+; CHECK-NEXT: [[TMP1:%.*]] = add i64 [[B:%.*]], -1
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i64 [[TMP1]], [[A:%.*]]
+; CHECK-NEXT: ret i1 [[TMP2]]
;
%1 = icmp uge i64 %a, %b
%2 = icmp ne i64 %b, 0
@@ -2284,10 +2282,9 @@ define i1 @and_icmp_ne_B_0_icmp_uge_A_B_commuted1(i64 %a, i64 %b) {
define i1 @and_icmp_ne_B_0_icmp_uge_A_B_commuted2(i64 %a, i64 %b) {
; CHECK-LABEL: @and_icmp_ne_B_0_icmp_uge_A_B_commuted2(
-; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i64 [[B:%.*]], 0
-; CHECK-NEXT: [[TMP2:%.*]] = icmp ule i64 [[B]], [[A:%.*]]
-; CHECK-NEXT: [[TMP3:%.*]] = and i1 [[TMP1]], [[TMP2]]
-; CHECK-NEXT: ret i1 [[TMP3]]
+; CHECK-NEXT: [[TMP1:%.*]] = add i64 [[B:%.*]], -1
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i64 [[TMP1]], [[A:%.*]]
+; CHECK-NEXT: ret i1 [[TMP2]]
;
%1 = icmp ne i64 %b, 0
%2 = icmp ule i64 %b, %a
@@ -2299,8 +2296,8 @@ define i1 @and_icmp_ne_B_0_icmp_uge_A_B_extra_use1(i64 %a, i64 %b) {
; CHECK-LABEL: @and_icmp_ne_B_0_icmp_uge_A_B_extra_use1(
; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i64 [[B:%.*]], 0
; CHECK-NEXT: call void @use_i1(i1 [[TMP1]])
-; CHECK-NEXT: [[TMP2:%.*]] = icmp uge i64 [[A:%.*]], [[B]]
-; CHECK-NEXT: [[TMP3:%.*]] = and i1 [[TMP1]], [[TMP2]]
+; CHECK-NEXT: [[TMP2:%.*]] = add i64 [[B]], -1
+; CHECK-NEXT: [[TMP3:%.*]] = icmp ult i64 [[TMP2]], [[A:%.*]]
; CHECK-NEXT: ret i1 [[TMP3]]
;
%1 = icmp ne i64 %b, 0
@@ -2312,10 +2309,10 @@ define i1 @and_icmp_ne_B_0_icmp_uge_A_B_extra_use1(i64 %a, i64 %b) {
define i1 @and_icmp_ne_B_0_icmp_uge_A_B_extra_use2(i64 %a, i64 %b) {
; CHECK-LABEL: @and_icmp_ne_B_0_icmp_uge_A_B_extra_use2(
-; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i64 [[B:%.*]], 0
-; CHECK-NEXT: [[TMP2:%.*]] = icmp uge i64 [[A:%.*]], [[B]]
-; CHECK-NEXT: call void @use_i1(i1 [[TMP2]])
-; CHECK-NEXT: [[TMP3:%.*]] = and i1 [[TMP1]], [[TMP2]]
+; CHECK-NEXT: [[TMP1:%.*]] = icmp uge i64 [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT: call void @use_i1(i1 [[TMP1]])
+; CHECK-NEXT: [[TMP2:%.*]] = add i64 [[B]], -1
+; CHECK-NEXT: [[TMP3:%.*]] = icmp ult i64 [[TMP2]], [[A]]
; CHECK-NEXT: ret i1 [[TMP3]]
;
%1 = icmp ne i64 %b, 0
@@ -2409,10 +2406,9 @@ define i1 @and_icmp_ne_B_0_icmp_uge_A_B_logical(i64 %a, i64 %b) {
define <2 x i1> @and_icmp_ne_B_0_icmp_uge_A_B_uniform(<2 x i64> %a, <2 x i64> %b) {
; CHECK-LABEL: @and_icmp_ne_B_0_icmp_uge_A_B_uniform(
-; CHECK-NEXT: [[TMP1:%.*]] = icmp ne <2 x i64> [[B:%.*]], zeroinitializer
-; CHECK-NEXT: [[TMP2:%.*]] = icmp uge <2 x i64> [[A:%.*]], [[B]]
-; CHECK-NEXT: [[TMP3:%.*]] = and <2 x i1> [[TMP1]], [[TMP2]]
-; CHECK-NEXT: ret <2 x i1> [[TMP3]]
+; CHECK-NEXT: [[TMP1:%.*]] = add <2 x i64> [[B:%.*]], <i64 -1, i64 -1>
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ult <2 x i64> [[TMP1]], [[A:%.*]]
+; CHECK-NEXT: ret <2 x i1> [[TMP2]]
;
%1 = icmp ne <2 x i64> %b, zeroinitializer
%2 = icmp uge <2 x i64> %a, %b
@@ -2422,10 +2418,9 @@ define <2 x i1> @and_icmp_ne_B_0_icmp_uge_A_B_uniform(<2 x i64> %a, <2 x i64> %b
define <2 x i1> @and_icmp_ne_B_0_icmp_uge_A_B_undef(<2 x i64> %a, <2 x i64> %b) {
; CHECK-LABEL: @and_icmp_ne_B_0_icmp_uge_A_B_undef(
-; CHECK-NEXT: [[TMP1:%.*]] = icmp ne <2 x i64> [[B:%.*]], <i64 0, i64 undef>
-; CHECK-NEXT: [[TMP2:%.*]] = icmp uge <2 x i64> [[A:%.*]], [[B]]
-; CHECK-NEXT: [[TMP3:%.*]] = and <2 x i1> [[TMP1]], [[TMP2]]
-; CHECK-NEXT: ret <2 x i1> [[TMP3]]
+; CHECK-NEXT: [[TMP1:%.*]] = add <2 x i64> [[B:%.*]], <i64 -1, i64 -1>
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ult <2 x i64> [[TMP1]], [[A:%.*]]
+; CHECK-NEXT: ret <2 x i1> [[TMP2]]
;
%1 = icmp ne <2 x i64> %b, <i64 0, i64 undef>
%2 = icmp uge <2 x i64> %a, %b
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