llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-llvm-transforms
Author: Yingwei Zheng (dtcxzyw)
<details>
<summary>Changes</summary>
This patch folds away the `inttoptr/ptrtoint` of the stored value by storing the original type. It will enable more optimizations.
An example in [z3/src/smt/smt_enode.h](https://github.com/Z3Prover/z3/blob/ebe5ebf0ae63bf520839b4d34d7b19e0af87fe36/src/smt/smt_enode.h#L41):
```
diff --git a/bench/z3/optimized/smt_enode.cpp.ll b/bench/z3/optimized/smt_enode.cpp.ll
index 6f42a9f4..91bc9b0e 100644
--- a/bench/z3/optimized/smt_enode.cpp.ll
+++ b/bench/z3/optimized/smt_enode.cpp.ll
@@ -4,12 +4,12 @@ target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:
target triple = "x86_64-unknown-linux-gnu"
%"class.std::ios_base::Init" = type { i8 }
-%"class.smt::eq_justification" = type { ptr }
%"class.smt::enode" = type { ptr, ptr, ptr, ptr, i32, i32, i32, i16, i32, i8, i8, %class.ptr_vector, %class.id_var_list, %"struct.smt::trans_justification", %class.approx_set, %class.approx_set, [0 x ptr] }
%class.ptr_vector = type { %class.vector }
%class.vector = type { ptr }
%class.id_var_list = type { i32, ptr }
%"struct.smt::trans_justification" = type { ptr, %"class.smt::eq_justification" }
+%"class.smt::eq_justification" = type { ptr }
%class.approx_set = type { %class.approx_set_tpl }
%class.approx_set_tpl = type { i64 }
%class.ast = type { i32, i24, i32, i32 }
@@ -454,7 +454,7 @@ $_ZTI11value_trailI10approx_setE = comdat any
@<!-- -->_ZStL8__ioinit = internal global %"class.std::ios_base::Init" zeroinitializer, align 1
@<!-- -->__dso_handle = external hidden global i8
-@<!-- -->_ZN3smtL21null_eq_justificationE = internal unnamed_addr global %"class.smt::eq_justification" zeroinitializer, align 8
+@<!-- -->_ZN3smtL21null_eq_justificationE.0 = internal unnamed_addr global i1 false, align 8
@.str = private unnamed_addr constant [2 x i8] c"#\00", align 1
@.str.7 = private unnamed_addr constant [8 x i8] c" -> #\00", align 1
@.str.8 = private unnamed_addr constant [9 x i8] c", lbls: \00", align 1
@@ -504,7 +504,8 @@ entry:
%m_next.i.i = getelementptr inbounds %"class.smt::enode", ptr %mem, i64 0, i32 12, i32 1
%m_justification.i.i = getelementptr inbounds %"class.smt::enode", ptr %mem, i64 0, i32 13, i32 1
tail call void @<!-- -->llvm.memset.p0.i64(ptr noundef nonnull align 8 dereferenceable(16) %m_next.i.i, i8 0, i64 16, i1 false)
- %0 = load i64, ptr @<!-- -->_ZN3smtL21null_eq_justificationE, align 8
+ %.b = load i1, ptr @<!-- -->_ZN3smtL21null_eq_justificationE.0, align 8
+ %0 = select i1 %.b, i64 3, i64 0
store i64 %0, ptr %m_justification.i.i, align 8
%m_lbls.i = getelementptr inbounds %"class.smt::enode", ptr %mem, i64 0, i32 14
tail call void @<!-- -->llvm.memset.p0.i64(ptr noundef nonnull align 8 dereferenceable(16) %m_lbls.i, i8 0, i64 16, i1 false)
@@ -2125,7 +2126,7 @@ define internal void @<!-- -->_GLOBAL__sub_I_smt_enode.cpp() #<!-- -->17 section ".text.startup"
entry:
tail call void @<!-- -->_ZNSt8ios_base4InitC1Ev(ptr noundef nonnull align 1 dereferenceable(1) @<!-- -->_ZStL8__ioinit)
%0 = tail call i32 @<!-- -->__cxa_atexit(ptr nonnull @<!-- -->_ZNSt8ios_base4InitD1Ev, ptr nonnull @<!-- -->_ZStL8__ioinit, ptr nonnull @<!-- -->__dso_handle) #<!-- -->20
- store ptr inttoptr (i64 3 to ptr), ptr @<!-- -->_ZN3smtL21null_eq_justificationE, align 8
+ store i1 true, ptr @<!-- -->_ZN3smtL21null_eq_justificationE.0, align 8
ret void
}
```
---
Full diff: https://github.com/llvm/llvm-project/pull/76339.diff
2 Files Affected:
- (modified) llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp (+14)
- (added) llvm/test/Transforms/InstCombine/store-inttoptr-ptrtoint.ll (+86)
``````````diff
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
+}
``````````
</details>
https://github.com/llvm/llvm-project/pull/76339