[llvm] f3190de - [IR] `IRBuilderBase::CreateAnd()`: short-circuit `x & 0` --> `0`
Roman Lebedev via llvm-commits
llvm-commits at lists.llvm.org
Wed Oct 27 08:03:49 PDT 2021
Author: Roman Lebedev
Date: 2021-10-27T18:01:06+03:00
New Revision: f3190dedeef9da2109ea57e4cb372f295ff53b88
URL: https://github.com/llvm/llvm-project/commit/f3190dedeef9da2109ea57e4cb372f295ff53b88
DIFF: https://github.com/llvm/llvm-project/commit/f3190dedeef9da2109ea57e4cb372f295ff53b88.diff
LOG: [IR] `IRBuilderBase::CreateAnd()`: short-circuit `x & 0` --> `0`
https://alive2.llvm.org/ce/z/YzPhSb
Refs. https://reviews.llvm.org/D109368#3089809
Added:
Modified:
clang/test/CodeGen/catch-nullptr-and-nonzero-offset.c
llvm/include/llvm/IR/IRBuilder.h
llvm/test/Transforms/LoopPredication/basic.ll
llvm/test/Transforms/LoopPredication/reverse.ll
Removed:
################################################################################
diff --git a/clang/test/CodeGen/catch-nullptr-and-nonzero-offset.c b/clang/test/CodeGen/catch-nullptr-and-nonzero-offset.c
index 12c4893ae1d1..191a6dac0a6b 100644
--- a/clang/test/CodeGen/catch-nullptr-and-nonzero-offset.c
+++ b/clang/test/CodeGen/catch-nullptr-and-nonzero-offset.c
@@ -172,13 +172,13 @@ char *nullptr_var(unsigned long offset) {
// CHECK-SANITIZE-NEXT: %[[COMPUTED_OFFSET:.*]] = extractvalue { i64, i1 } %[[COMPUTED_OFFSET_AGGREGATE]], 0, !nosanitize
// CHECK-SANITIZE-NEXT: %[[COMPUTED_GEP:.*]] = add i64 0, %[[COMPUTED_OFFSET]], !nosanitize
// CHECK-SANITIZE-NEXT: %[[COMPUTED_GEP_IS_NOT_NULL:.*]] = icmp ne i64 %[[COMPUTED_GEP]], 0, !nosanitize
- // CHECK-SANITIZE-C-NEXT: %[[BOTH_POINTERS_ARE_NULL_OR_BOTH_ARE_NONNULL:.*]] = and i1 %[[COMPUTED_GEP_IS_NOT_NULL]], false, !nosanitize
// CHECK-SANITIZE-CPP-NEXT: %[[BOTH_POINTERS_ARE_NULL_OR_BOTH_ARE_NONNULL:.*]] = icmp eq i1 false, %[[COMPUTED_GEP_IS_NOT_NULL]], !nosanitize
// CHECK-SANITIZE-NEXT: %[[COMPUTED_OFFSET_DID_NOT_OVERFLOW:.*]] = xor i1 %[[COMPUTED_OFFSET_OVERFLOWED]], true, !nosanitize
// CHECK-SANITIZE-NEXT: %[[COMPUTED_GEP_IS_UGE_BASE:.*]] = icmp uge i64 %[[COMPUTED_GEP]], 0, !nosanitize
// CHECK-SANITIZE-NEXT: %[[GEP_DID_NOT_OVERFLOW:.*]] = and i1 %[[COMPUTED_GEP_IS_UGE_BASE]], %[[COMPUTED_OFFSET_DID_NOT_OVERFLOW]], !nosanitize
- // CHECK-SANITIZE-NEXT: %[[GEP_IS_OKAY:.*]] = and i1 %[[BOTH_POINTERS_ARE_NULL_OR_BOTH_ARE_NONNULL]], %[[GEP_DID_NOT_OVERFLOW]], !nosanitize
- // CHECK-SANITIZE-NEXT: br i1 %[[GEP_IS_OKAY]], label %[[CONT:.*]], label %[[HANDLER_POINTER_OVERFLOW:[^,]+]],{{.*}} !nosanitize
+ // CHECK-SANITIZE-CPP-NEXT: %[[GEP_IS_OKAY:.*]] = and i1 %[[BOTH_POINTERS_ARE_NULL_OR_BOTH_ARE_NONNULL]], %[[GEP_DID_NOT_OVERFLOW]], !nosanitize
+ // CHECK-SANITIZE-C-NEXT: br i1 false, label %[[CONT:.*]], label %[[HANDLER_POINTER_OVERFLOW:[^,]+]],{{.*}} !nosanitize
+ // CHECK-SANITIZE-CPP-NEXT: br i1 %[[GEP_IS_OKAY]], label %[[CONT:.*]], label %[[HANDLER_POINTER_OVERFLOW:[^,]+]],{{.*}} !nosanitize
// CHECK-SANITIZE: [[HANDLER_POINTER_OVERFLOW]]:
// CHECK-SANITIZE-NORECOVER-NEXT: call void @__ubsan_handle_pointer_overflow_abort(i8* bitcast ({ {{{.*}}} }* @[[LINE_500]] to i8*), i64 0, i64 %[[COMPUTED_GEP]])
// CHECK-SANITIZE-RECOVER-NEXT: call void @__ubsan_handle_pointer_overflow(i8* bitcast ({ {{{.*}}} }* @[[LINE_500]] to i8*), i64 0, i64 %[[COMPUTED_GEP]])
diff --git a/llvm/include/llvm/IR/IRBuilder.h b/llvm/include/llvm/IR/IRBuilder.h
index 7b3a4c6d714a..c7899681835e 100644
--- a/llvm/include/llvm/IR/IRBuilder.h
+++ b/llvm/include/llvm/IR/IRBuilder.h
@@ -1362,9 +1362,13 @@ class IRBuilderBase {
Value *CreateAnd(Value *LHS, Value *RHS, const Twine &Name = "") {
if (!isa<Constant>(RHS) && isa<Constant>(LHS))
std::swap(LHS, RHS);
- if (auto *RC = dyn_cast<Constant>(RHS)) {
- if (isa<ConstantInt>(RC) && cast<ConstantInt>(RC)->isMinusOne())
+ if (auto RCI = dyn_cast<ConstantInt>(RHS)) {
+ if (RCI->isZero())
+ return RHS; // LHS & 0 -> 0
+ if (RCI->isMinusOne())
return LHS; // LHS & -1 -> LHS
+ }
+ if (auto *RC = dyn_cast<Constant>(RHS)) {
if (auto *LC = dyn_cast<Constant>(LHS))
return Insert(Folder.CreateAnd(LC, RC), Name);
}
diff --git a/llvm/test/Transforms/LoopPredication/basic.ll b/llvm/test/Transforms/LoopPredication/basic.ll
index 9972caae5713..1f64e4383c51 100644
--- a/llvm/test/Transforms/LoopPredication/basic.ll
+++ b/llvm/test/Transforms/LoopPredication/basic.ll
@@ -1554,12 +1554,11 @@ define i32 @provably_taken(i32* %array, i32* %length.ptr) {
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: [[LENGTH:%.*]] = load i32, i32* [[LENGTH_PTR:%.*]], align 4, !range [[RNG1:![0-9]+]]
; CHECK-NEXT: [[TMP0:%.*]] = icmp ult i32 0, [[LENGTH]]
-; CHECK-NEXT: [[TMP1:%.*]] = and i1 [[TMP0]], false
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER]] ]
-; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[TMP1]], i32 9) [ "deopt"() ]
+; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 false, i32 9) [ "deopt"() ]
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_I:%.*]] = load i32, i32* [[ARRAY_I_PTR]], align 4
diff --git a/llvm/test/Transforms/LoopPredication/reverse.ll b/llvm/test/Transforms/LoopPredication/reverse.ll
index 2a6d9fac6fe3..3e47f7ee7592 100644
--- a/llvm/test/Transforms/LoopPredication/reverse.ll
+++ b/llvm/test/Transforms/LoopPredication/reverse.ll
@@ -123,13 +123,12 @@ define i32 @unsigned_reverse_loop_n_to_0(i32* %array, i32 %length, i32 %n, i32 %
; CHECK: loop.preheader:
; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[N]], -1
; CHECK-NEXT: [[TMP1:%.*]] = icmp ult i32 [[TMP0]], [[LENGTH:%.*]]
-; CHECK-NEXT: [[TMP2:%.*]] = and i1 [[TMP1]], false
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[LOOP]] ], [ [[N]], [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[I_NEXT]] = add nsw i32 [[I]], -1
-; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[TMP2]], i32 9) [ "deopt"() ]
+; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 false, i32 9) [ "deopt"() ]
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I_NEXT]] to i64
; CHECK-NEXT: [[ARRAY_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_I:%.*]] = load i32, i32* [[ARRAY_I_PTR]], align 4
@@ -343,13 +342,12 @@ define i32 @unsigned_reverse_loop_n_to_1(i32* %array, i32 %length, i32 %n, i32 %
; CHECK: loop.preheader:
; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[N]], -1
; CHECK-NEXT: [[TMP1:%.*]] = icmp ult i32 [[TMP0]], [[LENGTH:%.*]]
-; CHECK-NEXT: [[TMP2:%.*]] = and i1 [[TMP1]], false
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[LOOP]] ], [ [[N]], [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[I_NEXT]] = add nsw i32 [[I]], -1
-; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[TMP2]], i32 9) [ "deopt"() ]
+; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 false, i32 9) [ "deopt"() ]
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I_NEXT]] to i64
; CHECK-NEXT: [[ARRAY_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_I:%.*]] = load i32, i32* [[ARRAY_I_PTR]], align 4
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