[llvm] 8bc038d - [InstComb] Allow more user for (add (ptrtoint %B), %O) to GEP transform. (#153566)
via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 22 02:17:16 PDT 2025
Author: Florian Hahn
Date: 2025-08-22T10:17:12+01:00
New Revision: 8bc038daf2d59496b33ac5825851f7c18541dab9
URL: https://github.com/llvm/llvm-project/commit/8bc038daf2d59496b33ac5825851f7c18541dab9
DIFF: https://github.com/llvm/llvm-project/commit/8bc038daf2d59496b33ac5825851f7c18541dab9.diff
LOG: [InstComb] Allow more user for (add (ptrtoint %B), %O) to GEP transform. (#153566)
Generalize the logic from
https://github.com/llvm/llvm-project/pull/153421 to support additional
cases where the pointer is only used as integer.
Alive2 Proof: https://alive2.llvm.org/ce/z/po58pP
This enables vectorizing std::find for some cases, if additional
assumptions are provided: https://godbolt.org/z/94oq3576E
Depends on https://github.com/llvm/llvm-project/pull/15342.
PR: https://github.com/llvm/llvm-project/pull/153566
Added:
llvm/test/Transforms/InstCombine/inttoptr-add-phi.ll
Modified:
llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
llvm/test/Transforms/PhaseOrdering/AArch64/std-find.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
index 6ef55d4bfc7d7..fdef49e310f81 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -2073,15 +2073,23 @@ Instruction *InstCombinerImpl::visitIntToPtr(IntToPtrInst &CI) {
}
// Replace (inttoptr (add (ptrtoint %Base), %Offset)) with
- // (getelementptr i8, %Base, %Offset) if all users are ICmps.
+ // (getelementptr i8, %Base, %Offset) if the pointer is only used as integer
+ // value.
Value *Base;
Value *Offset;
+ auto UsesPointerAsInt = [](User *U) {
+ if (isa<ICmpInst, PtrToIntInst>(U))
+ return true;
+ if (auto *P = dyn_cast<PHINode>(U))
+ return P->hasOneUse() && isa<ICmpInst, PtrToIntInst>(*P->user_begin());
+ return false;
+ };
if (match(CI.getOperand(0),
m_OneUse(m_c_Add(m_PtrToIntSameSize(DL, m_Value(Base)),
m_Value(Offset)))) &&
CI.getType()->getPointerAddressSpace() ==
Base->getType()->getPointerAddressSpace() &&
- all_of(CI.users(), IsaPred<ICmpInst>)) {
+ all_of(CI.users(), UsesPointerAsInt)) {
return GetElementPtrInst::Create(Builder.getInt8Ty(), Base, Offset);
}
diff --git a/llvm/test/Transforms/InstCombine/inttoptr-add-phi.ll b/llvm/test/Transforms/InstCombine/inttoptr-add-phi.ll
new file mode 100644
index 0000000000000..acceead23a5e5
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/inttoptr-add-phi.ll
@@ -0,0 +1,69 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -passes=instcombine -S %s | FileCheck %s
+
+define i64 @inttoptr_used_by_phi_with_ptrtoint(i1 %c, ptr %src, ptr %p2) {
+; CHECK-LABEL: define i64 @inttoptr_used_by_phi_with_ptrtoint(
+; CHECK-SAME: i1 [[C:%.*]], ptr [[SRC:%.*]], ptr [[P2:%.*]]) {
+; CHECK-NEXT: br i1 [[C]], label %[[THEN:.*]], label %[[ELSE:.*]]
+; CHECK: [[THEN]]:
+; CHECK-NEXT: [[P:%.*]] = getelementptr i8, ptr [[SRC]], i64 10
+; CHECK-NEXT: [[TMP1:%.*]] = ptrtoint ptr [[P]] to i64
+; CHECK-NEXT: br label %[[EXIT:.*]]
+; CHECK: [[ELSE]]:
+; CHECK-NEXT: br label %[[EXIT]]
+; CHECK: [[EXIT]]:
+; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ [[TMP1]], %[[THEN]] ], [ 0, %[[ELSE]] ]
+; CHECK-NEXT: ret i64 [[PHI]]
+;
+ %i = ptrtoint ptr %src to i64
+ %a = add i64 %i, 10
+ %p = inttoptr i64 %a to ptr
+ br i1 %c, label %then, label %else
+
+then:
+ br label %exit
+
+else:
+ br label %exit
+
+exit:
+ %phi = phi ptr [ %p, %then ], [ null, %else ]
+ %i.2 = ptrtoint ptr %phi to i64
+ ret i64 %i.2
+}
+
+declare void @foo(ptr)
+
+define i64 @inttoptr_used_by_phi_with_other_users(i1 %c, ptr %src, ptr %p2) {
+; CHECK-LABEL: define i64 @inttoptr_used_by_phi_with_other_users(
+; CHECK-SAME: i1 [[C:%.*]], ptr [[SRC:%.*]], ptr [[P2:%.*]]) {
+; CHECK-NEXT: [[I:%.*]] = ptrtoint ptr [[SRC]] to i64
+; CHECK-NEXT: [[A:%.*]] = add i64 [[I]], 10
+; CHECK-NEXT: br i1 [[C]], label %[[THEN:.*]], label %[[ELSE:.*]]
+; CHECK: [[THEN]]:
+; CHECK-NEXT: br label %[[EXIT:.*]]
+; CHECK: [[ELSE]]:
+; CHECK-NEXT: br label %[[EXIT]]
+; CHECK: [[EXIT]]:
+; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ [[A]], %[[THEN]] ], [ 0, %[[ELSE]] ]
+; CHECK-NEXT: [[P:%.*]] = inttoptr i64 [[A]] to ptr
+; CHECK-NEXT: call void @foo(ptr [[P]])
+; CHECK-NEXT: ret i64 [[PHI]]
+;
+ %i = ptrtoint ptr %src to i64
+ %a = add i64 %i, 10
+ %p = inttoptr i64 %a to ptr
+ br i1 %c, label %then, label %else
+
+then:
+ br label %exit
+
+else:
+ br label %exit
+
+exit:
+ %phi = phi ptr [ %p, %then ], [ null, %else ]
+ call void @foo(ptr %p)
+ %i.2 = ptrtoint ptr %phi to i64
+ ret i64 %i.2
+}
diff --git a/llvm/test/Transforms/PhaseOrdering/AArch64/std-find.ll b/llvm/test/Transforms/PhaseOrdering/AArch64/std-find.ll
index fa25af5f3467d..0ef21adff74a6 100644
--- a/llvm/test/Transforms/PhaseOrdering/AArch64/std-find.ll
+++ b/llvm/test/Transforms/PhaseOrdering/AArch64/std-find.ll
@@ -9,27 +9,34 @@ define i64 @std_find_i16_constant_offset_with_assumptions(ptr %first.coerce, i16
; CHECK-NEXT: [[ENTRY:.*]]:
; CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[FIRST_COERCE]], i64 2) ]
; CHECK-NEXT: call void @llvm.assume(i1 true) [ "dereferenceable"(ptr [[FIRST_COERCE]], i64 256) ]
-; CHECK-NEXT: [[TMP0:%.*]] = ptrtoint ptr [[FIRST_COERCE]] to i64
-; CHECK-NEXT: [[COERCE_VAL_PI_I:%.*]] = add i64 [[TMP0]], 256
-; CHECK-NEXT: [[COERCE_VAL_IP:%.*]] = inttoptr i64 [[COERCE_VAL_PI_I]] to ptr
-; CHECK-NEXT: [[CMP_NOT6_I_I:%.*]] = icmp eq ptr [[FIRST_COERCE]], [[COERCE_VAL_IP]]
-; CHECK-NEXT: br i1 [[CMP_NOT6_I_I]], label %[[RETURN:.*]], label %[[LOOP_HEADER:.*]]
-; CHECK: [[LOOP_HEADER]]:
-; CHECK-NEXT: [[PTR_IV:%.*]] = phi ptr [ [[PTR_IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ], [ [[FIRST_COERCE]], %[[ENTRY]] ]
-; CHECK-NEXT: [[TMP1:%.*]] = load i16, ptr [[PTR_IV]], align 2
-; CHECK-NEXT: [[CMP2_I_I:%.*]] = icmp eq i16 [[TMP1]], [[S]]
-; CHECK-NEXT: br i1 [[CMP2_I_I]], label %[[RETURN_LOOPEXIT:.*]], label %[[LOOP_LATCH]]
-; CHECK: [[LOOP_LATCH]]:
-; CHECK-NEXT: [[PTR_IV_NEXT]] = getelementptr inbounds nuw i8, ptr [[PTR_IV]], i64 2
-; CHECK-NEXT: [[CMP_NOT_I_I:%.*]] = icmp eq ptr [[PTR_IV_NEXT]], [[COERCE_VAL_IP]]
-; CHECK-NEXT: br i1 [[CMP_NOT_I_I]], label %[[RETURN_LOOPEXIT]], label %[[LOOP_HEADER]]
-; CHECK: [[RETURN_LOOPEXIT]]:
-; CHECK-NEXT: [[MERGE_PH:%.*]] = phi ptr [ [[COERCE_VAL_IP]], %[[LOOP_LATCH]] ], [ [[PTR_IV]], %[[LOOP_HEADER]] ]
-; CHECK-NEXT: [[DOTPRE:%.*]] = ptrtoint ptr [[MERGE_PH]] to i64
+; CHECK-NEXT: [[COERCE_VAL_IP:%.*]] = getelementptr i8, ptr [[FIRST_COERCE]], i64 256
+; CHECK-NEXT: [[BROADCAST_SPLATINSERT:%.*]] = insertelement <8 x i16> poison, i16 [[S]], i64 0
+; CHECK-NEXT: [[BROADCAST_SPLAT:%.*]] = shufflevector <8 x i16> [[BROADCAST_SPLATINSERT]], <8 x i16> poison, <8 x i32> zeroinitializer
+; CHECK-NEXT: br label %[[VECTOR_BODY:.*]]
+; CHECK: [[VECTOR_BODY]]:
+; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT: [[OFFSET_IDX:%.*]] = shl i64 [[INDEX]], 1
+; CHECK-NEXT: [[NEXT_GEP:%.*]] = getelementptr i8, ptr [[FIRST_COERCE]], i64 [[OFFSET_IDX]]
+; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <8 x i16>, ptr [[NEXT_GEP]], align 2
+; CHECK-NEXT: [[TMP0:%.*]] = icmp eq <8 x i16> [[WIDE_LOAD]], [[BROADCAST_SPLAT]]
+; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 8
+; CHECK-NEXT: [[TMP1:%.*]] = bitcast <8 x i1> [[TMP0]] to i8
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i8 [[TMP1]], 0
+; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i64 [[INDEX_NEXT]], 128
+; CHECK-NEXT: [[TMP4:%.*]] = or i1 [[TMP2]], [[TMP3]]
+; CHECK-NEXT: br i1 [[TMP4]], label %[[MIDDLE_SPLIT:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
+; CHECK: [[MIDDLE_SPLIT]]:
+; CHECK-NEXT: br i1 [[TMP2]], label %[[VECTOR_EARLY_EXIT:.*]], label %[[RETURN:.*]]
+; CHECK: [[VECTOR_EARLY_EXIT]]:
+; CHECK-NEXT: [[TMP5:%.*]] = tail call i64 @llvm.experimental.cttz.elts.i64.v8i1(<8 x i1> [[TMP0]], i1 true)
+; CHECK-NEXT: [[TMP6:%.*]] = add i64 [[INDEX]], [[TMP5]]
+; CHECK-NEXT: [[TMP7:%.*]] = shl i64 [[TMP6]], 1
+; CHECK-NEXT: [[TMP8:%.*]] = getelementptr i8, ptr [[FIRST_COERCE]], i64 [[TMP7]]
; CHECK-NEXT: br label %[[RETURN]]
; CHECK: [[RETURN]]:
-; CHECK-NEXT: [[RES_PRE_PHI:%.*]] = phi i64 [ [[DOTPRE]], %[[RETURN_LOOPEXIT]] ], [ [[TMP0]], %[[ENTRY]] ]
-; CHECK-NEXT: ret i64 [[RES_PRE_PHI]]
+; CHECK-NEXT: [[__FIRST_ADDR_0_LCSSA_I_I_PH:%.*]] = phi ptr [ [[TMP8]], %[[VECTOR_EARLY_EXIT]] ], [ [[COERCE_VAL_IP]], %[[MIDDLE_SPLIT]] ]
+; CHECK-NEXT: [[DOTPRE:%.*]] = ptrtoint ptr [[__FIRST_ADDR_0_LCSSA_I_I_PH]] to i64
+; CHECK-NEXT: ret i64 [[DOTPRE]]
;
entry:
%first = alloca { ptr }, align 8
@@ -71,27 +78,21 @@ define i64 @std_find_i16_constant_offset_no_assumptions(ptr %first.coerce, i16 n
; CHECK-LABEL: define i64 @std_find_i16_constant_offset_no_assumptions(
; CHECK-SAME: ptr [[FIRST_COERCE:%.*]], i16 noundef signext [[S:%.*]]) local_unnamed_addr #[[ATTR1:[0-9]+]] {
; CHECK-NEXT: [[ENTRY:.*]]:
-; CHECK-NEXT: [[TMP0:%.*]] = ptrtoint ptr [[FIRST_COERCE]] to i64
-; CHECK-NEXT: [[COERCE_VAL_PI_I:%.*]] = add i64 [[TMP0]], 256
-; CHECK-NEXT: [[COERCE_VAL_IP:%.*]] = inttoptr i64 [[COERCE_VAL_PI_I]] to ptr
-; CHECK-NEXT: [[CMP_NOT6_I_I:%.*]] = icmp eq ptr [[FIRST_COERCE]], [[COERCE_VAL_IP]]
-; CHECK-NEXT: br i1 [[CMP_NOT6_I_I]], label %[[RETURN:.*]], label %[[LOOP_HEADER:.*]]
+; CHECK-NEXT: [[COERCE_VAL_IP:%.*]] = getelementptr i8, ptr [[FIRST_COERCE]], i64 256
+; CHECK-NEXT: br label %[[LOOP_HEADER:.*]]
; CHECK: [[LOOP_HEADER]]:
-; CHECK-NEXT: [[PTR_IV:%.*]] = phi ptr [ [[PTR_IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ], [ [[FIRST_COERCE]], %[[ENTRY]] ]
+; CHECK-NEXT: [[PTR_IV:%.*]] = phi ptr [ [[FIRST_COERCE]], %[[ENTRY]] ], [ [[PTR_IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ]
; CHECK-NEXT: [[TMP1:%.*]] = load i16, ptr [[PTR_IV]], align 2
; CHECK-NEXT: [[CMP2_I_I:%.*]] = icmp eq i16 [[TMP1]], [[S]]
-; CHECK-NEXT: br i1 [[CMP2_I_I]], label %[[RETURN_LOOPEXIT:.*]], label %[[LOOP_LATCH]]
+; CHECK-NEXT: br i1 [[CMP2_I_I]], label %[[RETURN:.*]], label %[[LOOP_LATCH]]
; CHECK: [[LOOP_LATCH]]:
; CHECK-NEXT: [[PTR_IV_NEXT]] = getelementptr inbounds nuw i8, ptr [[PTR_IV]], i64 2
; CHECK-NEXT: [[CMP_NOT_I_I:%.*]] = icmp eq ptr [[PTR_IV_NEXT]], [[COERCE_VAL_IP]]
-; CHECK-NEXT: br i1 [[CMP_NOT_I_I]], label %[[RETURN_LOOPEXIT]], label %[[LOOP_HEADER]]
-; CHECK: [[RETURN_LOOPEXIT]]:
+; CHECK-NEXT: br i1 [[CMP_NOT_I_I]], label %[[RETURN]], label %[[LOOP_HEADER]]
+; CHECK: [[RETURN]]:
; CHECK-NEXT: [[MERGE_PH:%.*]] = phi ptr [ [[COERCE_VAL_IP]], %[[LOOP_LATCH]] ], [ [[PTR_IV]], %[[LOOP_HEADER]] ]
; CHECK-NEXT: [[DOTPRE:%.*]] = ptrtoint ptr [[MERGE_PH]] to i64
-; CHECK-NEXT: br label %[[RETURN]]
-; CHECK: [[RETURN]]:
-; CHECK-NEXT: [[RES_PRE_PHI:%.*]] = phi i64 [ [[DOTPRE]], %[[RETURN_LOOPEXIT]] ], [ [[TMP0]], %[[ENTRY]] ]
-; CHECK-NEXT: ret i64 [[RES_PRE_PHI]]
+; CHECK-NEXT: ret i64 [[DOTPRE]]
;
entry:
%first = alloca { ptr }, align 8
@@ -128,3 +129,8 @@ return:
}
declare void @llvm.assume(i1 noundef)
+;.
+; CHECK: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]], [[META2:![0-9]+]]}
+; CHECK: [[META1]] = !{!"llvm.loop.isvectorized", i32 1}
+; CHECK: [[META2]] = !{!"llvm.loop.unroll.runtime.disable"}
+;.
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