[InstCombine] Canonicalize the stored value type with inttoptr/ptrtoint #76339
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@llvm/pr-subscribers-llvm-transforms Author: Yingwei Zheng (dtcxzyw) ChangesThis patch folds away the Full diff: https://github.com/llvm/llvm-project/pull/76339.diff 2 Files Affected:
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index bb2a77daa60a76..7a5a811c5e0b2e 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -1209,6 +1209,20 @@ static bool combineStoreToValueType(InstCombinerImpl &IC, StoreInst &SI) {
return true;
}
+ // Fold away inttoptr/ptrtoint of the stored value by storing the original
+ // type.
+ Value *X;
+ if (match(V, m_IntToPtr(m_Value(X))) || match(V, m_PtrToInt(m_Value(X)))) {
+ const DataLayout &DL = IC.getDataLayout();
+ if (DL.getTypeStoreSize(V->getType()->getScalarType()) !=
+ DL.getTypeStoreSize(X->getType()->getScalarType()))
+ return false;
+ if (!SI.isAtomic() || isSupportedAtomicType(X->getType())) {
+ combineStoreToNewValue(IC, SI, X);
+ return true;
+ }
+ }
+
// FIXME: We should also canonicalize stores of vectors when their elements
// are cast to other types.
return false;
diff --git a/llvm/test/Transforms/InstCombine/store-inttoptr-ptrtoint.ll b/llvm/test/Transforms/InstCombine/store-inttoptr-ptrtoint.ll
new file mode 100644
index 00000000000000..8336f5eccd3841
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/store-inttoptr-ptrtoint.ll
@@ -0,0 +1,86 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+
+declare void @use64(i64)
+declare void @useptr(ptr)
+define void @test_inttoptr(ptr %p, i64 %x) {
+; CHECK-LABEL: define void @test_inttoptr(
+; CHECK-SAME: ptr [[P:%.*]], i64 [[X:%.*]]) {
+; CHECK-NEXT: store i64 [[X]], ptr [[P]], align 8
+; CHECK-NEXT: ret void
+;
+ %y = inttoptr i64 %x to ptr
+ store ptr %y, ptr %p, align 8
+ ret void
+}
+define void @test_inttoptr_multiuse(ptr %p, i64 %x) {
+; CHECK-LABEL: define void @test_inttoptr_multiuse(
+; CHECK-SAME: ptr [[P:%.*]], i64 [[X:%.*]]) {
+; CHECK-NEXT: [[Y:%.*]] = inttoptr i64 [[X]] to ptr
+; CHECK-NEXT: call void @useptr(ptr [[Y]])
+; CHECK-NEXT: store i64 [[X]], ptr [[P]], align 8
+; CHECK-NEXT: ret void
+;
+ %y = inttoptr i64 %x to ptr
+ call void @useptr(ptr %y)
+ store ptr %y, ptr %p, align 8
+ ret void
+}
+define void @test_inttoptr_constant_expr(ptr %p) {
+; CHECK-LABEL: define void @test_inttoptr_constant_expr(
+; CHECK-SAME: ptr [[P:%.*]]) {
+; CHECK-NEXT: store i64 65, ptr [[P]], align 8
+; CHECK-NEXT: ret void
+;
+ store ptr inttoptr (i64 65 to ptr), ptr %p, align 8
+ ret void
+}
+define void @test_ptrtoint(ptr %p, ptr %x) {
+; CHECK-LABEL: define void @test_ptrtoint(
+; CHECK-SAME: ptr [[P:%.*]], ptr [[X:%.*]]) {
+; CHECK-NEXT: store ptr [[X]], ptr [[P]], align 8
+; CHECK-NEXT: ret void
+;
+ %y = ptrtoint ptr %x to i64
+ store i64 %y, ptr %p, align 8
+ ret void
+}
+define void @test_ptrtoint_multiuse(ptr %p, ptr %x) {
+; CHECK-LABEL: define void @test_ptrtoint_multiuse(
+; CHECK-SAME: ptr [[P:%.*]], ptr [[X:%.*]]) {
+; CHECK-NEXT: [[Y:%.*]] = ptrtoint ptr [[X]] to i64
+; CHECK-NEXT: call void @use64(i64 [[Y]])
+; CHECK-NEXT: store ptr [[X]], ptr [[P]], align 8
+; CHECK-NEXT: ret void
+;
+ %y = ptrtoint ptr %x to i64
+ call void @use64(i64 %y)
+ store i64 %y, ptr %p, align 8
+ ret void
+}
+; Negative tests
+define void @test_inttoptr_mismatched_size(ptr %p, i32 %x) {
+; CHECK-LABEL: define void @test_inttoptr_mismatched_size(
+; CHECK-SAME: ptr [[P:%.*]], i32 [[X:%.*]]) {
+; CHECK-NEXT: [[TMP1:%.*]] = zext i32 [[X]] to i64
+; CHECK-NEXT: store i64 [[TMP1]], ptr [[P]], align 8
+; CHECK-NEXT: ret void
+;
+ %y = inttoptr i32 %x to ptr
+ store ptr %y, ptr %p, align 8
+ ret void
+}
+define void @test_ptrtoint_mismatched_size(ptr %p, ptr %x) {
+; CHECK-LABEL: define void @test_ptrtoint_mismatched_size(
+; CHECK-SAME: ptr [[P:%.*]], ptr [[X:%.*]]) {
+; CHECK-NEXT: [[TMP1:%.*]] = ptrtoint ptr [[X]] to i64
+; CHECK-NEXT: [[Y:%.*]] = trunc i64 [[TMP1]] to i32
+; CHECK-NEXT: store i32 [[Y]], ptr [[P]], align 4
+; CHECK-NEXT: ret void
+;
+ %y = ptrtoint ptr %x to i32
+ store i32 %y, ptr %p, align 4
+ ret void
+}
|
dtcxzyw
added a commit
to dtcxzyw/llvm-opt-benchmark
that referenced
this pull request
Dec 24, 2023
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This looks like the store variant of the load fold we explicitly removed in 544a6aa. Generally we don't want to introduce type-punning between pointers and integers, as the semantics are very unclear (but it's very likely that at least one of these transforms is unsound). |
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Thank you for the explanation! |
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This patch folds away the
inttoptr/ptrtointof the stored value by storing the original type. It will enable more optimizations.An example in z3/src/smt/smt_enode.h: