[PATCH] D59471: [InstCombine] Fold add nuw + uadd.with.overflow
Dan Robertson via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Mon Mar 18 14:57:43 PDT 2019
dlrobertson updated this revision to Diff 191184.
dlrobertson added a comment.
Rebased on master
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D59471/new/
https://reviews.llvm.org/D59471
Files:
llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
llvm/test/Transforms/InstCombine/uadd-with-overflow.ll
Index: llvm/test/Transforms/InstCombine/uadd-with-overflow.ll
===================================================================
--- llvm/test/Transforms/InstCombine/uadd-with-overflow.ll
+++ llvm/test/Transforms/InstCombine/uadd-with-overflow.ll
@@ -11,9 +11,8 @@
define { i32, i1 } @simple_fold(i32 %x) {
; CHECK-LABEL: @simple_fold(
-; CHECK-NEXT: [[A:%.*]] = add nuw i32 [[X:%.*]], 7
-; CHECK-NEXT: [[B:%.*]] = tail call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 [[A]], i32 13)
-; CHECK-NEXT: ret { i32, i1 } [[B]]
+; CHECK-NEXT: [[TMP1:%.*]] = call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 [[X:%.*]], i32 20)
+; CHECK-NEXT: ret { i32, i1 } [[TMP1]]
;
%a = add nuw i32 %x, 7
%b = tail call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 %a, i32 13)
@@ -22,9 +21,8 @@
define { i8, i1 } @fold_on_constant_add_no_overflow(i8 %x) {
; CHECK-LABEL: @fold_on_constant_add_no_overflow(
-; CHECK-NEXT: [[A:%.*]] = add nuw i8 [[X:%.*]], -56
-; CHECK-NEXT: [[B:%.*]] = tail call { i8, i1 } @llvm.uadd.with.overflow.i8(i8 [[A]], i8 55)
-; CHECK-NEXT: ret { i8, i1 } [[B]]
+; CHECK-NEXT: [[TMP1:%.*]] = call { i8, i1 } @llvm.uadd.with.overflow.i8(i8 [[X:%.*]], i8 -1)
+; CHECK-NEXT: ret { i8, i1 } [[TMP1]]
;
%a = add nuw i8 %x, 200
%b = tail call { i8, i1 } @llvm.uadd.with.overflow.i8(i8 %a, i8 55)
@@ -66,9 +64,8 @@
define { <2 x i32>, <2 x i1> } @fold_simple_splat_constant(<2 x i32> %x) {
; CHECK-LABEL: @fold_simple_splat_constant(
-; CHECK-NEXT: [[A:%.*]] = add nuw <2 x i32> [[X:%.*]], <i32 12, i32 12>
-; CHECK-NEXT: [[B:%.*]] = tail call { <2 x i32>, <2 x i1> } @llvm.uadd.with.overflow.v2i32(<2 x i32> [[A]], <2 x i32> <i32 30, i32 30>)
-; CHECK-NEXT: ret { <2 x i32>, <2 x i1> } [[B]]
+; CHECK-NEXT: [[TMP1:%.*]] = call { <2 x i32>, <2 x i1> } @llvm.uadd.with.overflow.v2i32(<2 x i32> [[X:%.*]], <2 x i32> <i32 42, i32 42>)
+; CHECK-NEXT: ret { <2 x i32>, <2 x i1> } [[TMP1]]
;
%a = add nuw <2 x i32> %x, <i32 12, i32 12>
%b = tail call { <2 x i32>, <2 x i1> } @llvm.uadd.with.overflow.v2i32(<2 x i32> %a, <2 x i32> <i32 30, i32 30>)
@@ -99,9 +96,8 @@
define { i32, i1 } @fold_nuwnsw(i32 %x) {
; CHECK-LABEL: @fold_nuwnsw(
-; CHECK-NEXT: [[A:%.*]] = add nuw nsw i32 [[X:%.*]], 12
-; CHECK-NEXT: [[B:%.*]] = tail call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 [[A]], i32 30)
-; CHECK-NEXT: ret { i32, i1 } [[B]]
+; CHECK-NEXT: [[TMP1:%.*]] = call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 [[X:%.*]], i32 42)
+; CHECK-NEXT: ret { i32, i1 } [[TMP1]]
;
%a = add nuw nsw i32 %x, 12
%b = tail call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 %a, i32 30)
Index: llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -2071,7 +2071,30 @@
break;
}
- case Intrinsic::uadd_with_overflow:
+ case Intrinsic::uadd_with_overflow: {
+ if (Instruction *I = canonicalizeConstantArg0ToArg1(CI))
+ return I;
+ if (Instruction *I = foldIntrinsicWithOverflowCommon(II))
+ return I;
+
+ // Given 2 constant operands whose sum does not overflow:
+ // uaddo (X +nuw C0), C1 -> uaddo X, C0 + C1
+ Value *X;
+ const APInt *C0, *C1;
+ Value *Arg0 = II->getArgOperand(0);
+ Value *Arg1 = II->getArgOperand(1);
+ if (match(Arg0, m_NUWAdd(m_Value(X), m_APInt(C0))) &&
+ match(Arg1, m_APInt(C1))) {
+ bool Overflow;
+ APInt NewC = C1->uadd_ov(*C0, Overflow);
+ if (!Overflow)
+ return replaceInstUsesWith(
+ *II, Builder.CreateBinaryIntrinsic(
+ Intrinsic::uadd_with_overflow, X,
+ ConstantInt::get(Arg1->getType(), NewC)));
+ }
+ break;
+ }
case Intrinsic::umul_with_overflow:
case Intrinsic::smul_with_overflow:
if (Instruction *I = canonicalizeConstantArg0ToArg1(CI))
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