[InstComb] Allow more user for (add (ptrtoint %B), %O) to GEP transform. #153566

fhahn · 2025-08-14T10:36:22Z

Generalize the logic from
#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 #153421 (included in
the PR).

Replace inttoptr (add (ptrtoint %B), %O) with (getelementptr i8, %B, %o) if all users are ICmp instruction, which in turn means only the address value is compared. We should be able to do this, if the src pointer, the integer type and the destination pointer types have the same bitwidth and address space. A common source of such (inttoptr (add (ptrtoint %B), %O)) is from various iterations in libc++. In practice this triggers in a number of files in Clang and various open source projects, including cppcheck, diamond, llama and more. Alive2 Proof with constant offset: https://alive2.llvm.org/ce/z/K_5N_B

Generalize the logic from llvm#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 llvm#153421 (included in the PR).

llvmbot · 2025-08-14T10:36:56Z

@llvm/pr-subscribers-llvm-transforms

Author: Florian Hahn (fhahn)

Changes

Generalize the logic from
#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 #153421 (included in
the PR).

Full diff: https://github.com/llvm/llvm-project/pull/153566.diff

4 Files Affected:

(modified) llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp (+20)
(modified) llvm/test/Transforms/InstCombine/fold-bin-operand.ll (+151-1)
(added) llvm/test/Transforms/InstCombine/inttoptr-add-phi.ll (+70)
(modified) llvm/test/Transforms/PhaseOrdering/AArch64/std-find.ll (+38-32)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
index a43a6ee1f58b0..dcab043c14fa5 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -2073,6 +2073,26 @@ Instruction *InstCombinerImpl::visitIntToPtr(IntToPtrInst &CI) {
     return new IntToPtrInst(P, CI.getType());
   }
 
+  // Replace (inttoptr (add (ptrtoint %Base), %Offset)) with
+  // (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_Add(m_PtrToIntSameSize(DL, m_Value(Base)), m_Value(Offset))) &&
+      CI.getType()->getPointerAddressSpace() ==
+          Base->getType()->getPointerAddressSpace() &&
+      all_of(CI.users(), UsesPointerAsInt)) {
+    return GetElementPtrInst::Create(Builder.getInt8Ty(), Base, Offset);
+  }
+
   if (Instruction *I = commonCastTransforms(CI))
     return I;
 
diff --git a/llvm/test/Transforms/InstCombine/fold-bin-operand.ll b/llvm/test/Transforms/InstCombine/fold-bin-operand.ll
index f28262b2a77e0..f596bc5d226be 100644
--- a/llvm/test/Transforms/InstCombine/fold-bin-operand.ll
+++ b/llvm/test/Transforms/InstCombine/fold-bin-operand.ll
@@ -1,6 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -passes=instcombine -S | FileCheck %s
-target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
+target datalayout = "E-p:64:64:64-p1:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
 
 define i1 @f(i1 %x) {
 ; CHECK-LABEL: @f(
@@ -30,6 +30,156 @@ define i32 @g(i32 %x) {
   ret i32 %b
 }
 
+define i1 @inttoptr_add_ptrtoint_used_by_single_icmp(ptr %src, ptr %p2) {
+; CHECK-LABEL: @inttoptr_add_ptrtoint_used_by_single_icmp(
+; CHECK-NEXT:    [[P2:%.*]] = getelementptr i8, ptr [[SRC:%.*]], i64 10
+; CHECK-NEXT:    [[C:%.*]] = icmp eq ptr [[P2]], [[P:%.*]]
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %i = ptrtoint ptr %src to i64
+  %a = add i64 %i, 10
+  %p = inttoptr i64 %a to ptr
+  %c = icmp eq ptr %p, %p2
+  ret i1 %c
+}
+
+define i1 @inttoptr_add_ptrtoint_used_by_single_icmp_different_src_address_spaces(ptr addrspace(1) %src, ptr %p2) {
+; CHECK-LABEL: @inttoptr_add_ptrtoint_used_by_single_icmp_different_src_address_spaces(
+; CHECK-NEXT:    [[I:%.*]] = ptrtoint ptr addrspace(1) [[SRC:%.*]] to i64
+; CHECK-NEXT:    [[A:%.*]] = add i64 [[I]], 10
+; CHECK-NEXT:    [[P:%.*]] = inttoptr i64 [[A]] to ptr
+; CHECK-NEXT:    [[C:%.*]] = icmp eq ptr [[P2:%.*]], [[P]]
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %i = ptrtoint ptr addrspace(1) %src to i64
+  %a = add i64 %i, 10
+  %p = inttoptr i64 %a to ptr
+  %c = icmp eq ptr %p, %p2
+  ret i1 %c
+}
+
+define i1 @inttoptr_add_ptrtoint_used_by_single_icmp_different_dst_address_spaces(ptr %src, ptr addrspace(1) %p2) {
+; CHECK-LABEL: @inttoptr_add_ptrtoint_used_by_single_icmp_different_dst_address_spaces(
+; CHECK-NEXT:    [[I:%.*]] = ptrtoint ptr [[SRC:%.*]] to i64
+; CHECK-NEXT:    [[A:%.*]] = add i64 [[I]], 10
+; CHECK-NEXT:    [[P:%.*]] = inttoptr i64 [[A]] to ptr addrspace(1)
+; CHECK-NEXT:    [[C:%.*]] = icmp eq ptr addrspace(1) [[P2:%.*]], [[P]]
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %i = ptrtoint ptr %src to i64
+  %a = add i64 %i, 10
+  %p = inttoptr i64 %a to ptr addrspace(1)
+  %c = icmp eq ptr addrspace(1) %p, %p2
+  ret i1 %c
+}
+
+define i1 @inttoptr_add_ptrtoint_used_by_single_icmp_int_type_does_not_match_ptr_ty(ptr %src, ptr %p2) {
+; CHECK-LABEL: @inttoptr_add_ptrtoint_used_by_single_icmp_int_type_does_not_match_ptr_ty(
+; CHECK-NEXT:    [[TMP1:%.*]] = ptrtoint ptr [[SRC:%.*]] to i64
+; CHECK-NEXT:    [[I:%.*]] = trunc i64 [[TMP1]] to i8
+; CHECK-NEXT:    [[A:%.*]] = add i8 [[I]], 10
+; CHECK-NEXT:    [[TMP2:%.*]] = zext i8 [[A]] to i64
+; CHECK-NEXT:    [[P:%.*]] = inttoptr i64 [[TMP2]] to ptr
+; CHECK-NEXT:    [[C:%.*]] = icmp eq ptr [[P2:%.*]], [[P]]
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %i = ptrtoint ptr %src to i8
+  %a = add i8 %i, 10
+  %p = inttoptr i8 %a to ptr
+  %c = icmp eq ptr %p, %p2
+  ret i1 %c
+}
+
+define i1 @multiple_inttoptr_add_ptrtoint_used_by_single_icmp(ptr %src) {
+; CHECK-LABEL: @multiple_inttoptr_add_ptrtoint_used_by_single_icmp(
+; CHECK-NEXT:    ret i1 false
+;
+  %i = ptrtoint ptr %src to i64
+  %a = add i64 %i, 10
+  %p = inttoptr i64 %a to ptr
+  %a.2 = add i64 %i, 11
+  %p.2 = inttoptr i64 %a.2 to ptr
+  %c = icmp eq ptr %p, %p.2
+  ret i1 %c
+}
+
+define i1 @multiple_inttoptr_add_ptrtoint_used_by_single_icmp_non_constant_offset(ptr %src, i64 %off.1, i64 %off.2) {
+; CHECK-LABEL: @multiple_inttoptr_add_ptrtoint_used_by_single_icmp_non_constant_offset(
+; CHECK-NEXT:    [[C:%.*]] = icmp eq i64 [[OFF_1:%.*]], [[OFF_2:%.*]]
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %i = ptrtoint ptr %src to i64
+  %a = add i64 %i, %off.1
+  %p = inttoptr i64 %a to ptr
+  %a.2 = add i64 %i, %off.2
+  %p.2 = inttoptr i64 %a.2 to ptr
+  %c = icmp eq ptr %p, %p.2
+  ret i1 %c
+}
+
+define i1 @inttoptr_add_ptrtoint_used_by_single_icmp_in_different_bb(i1 %bc, ptr %src, ptr %p2) {
+; CHECK-LABEL: @inttoptr_add_ptrtoint_used_by_single_icmp_in_different_bb(
+; CHECK-NEXT:    br i1 [[BC:%.*]], label [[THEN:%.*]], label [[ELSE:%.*]]
+; CHECK:       then:
+; CHECK-NEXT:    [[P2:%.*]] = getelementptr i8, ptr [[SRC:%.*]], i64 10
+; CHECK-NEXT:    [[C:%.*]] = icmp eq ptr [[P2]], [[P:%.*]]
+; CHECK-NEXT:    ret i1 [[C]]
+; CHECK:       else:
+; CHECK-NEXT:    ret i1 false
+;
+  %i = ptrtoint ptr %src to i64
+  %a = add i64 %i, 10
+  %p = inttoptr i64 %a to ptr
+  br i1 %bc, label %then, label %else
+
+then:
+  %c = icmp eq ptr %p, %p2
+  ret i1 %c
+
+else:
+  ret i1 false
+}
+
+define i1 @inttoptr_add_ptrtoint_used_by_multiple_icmps(ptr %src, ptr %p2, ptr %p3) {
+; CHECK-LABEL: @inttoptr_add_ptrtoint_used_by_multiple_icmps(
+; CHECK-NEXT:    [[P2:%.*]] = getelementptr i8, ptr [[SRC:%.*]], i64 10
+; CHECK-NEXT:    [[C_1:%.*]] = icmp eq ptr [[P2]], [[P:%.*]]
+; CHECK-NEXT:    [[C_2:%.*]] = icmp eq ptr [[P2]], [[P3:%.*]]
+; CHECK-NEXT:    [[XOR:%.*]] = xor i1 [[C_1]], [[C_2]]
+; CHECK-NEXT:    ret i1 [[XOR]]
+;
+  %i = ptrtoint ptr %src to i64
+  %a = add i64 %i, 10
+  %p = inttoptr i64 %a to ptr
+  %c.1 = icmp eq ptr %p, %p2
+  %c.2 = icmp eq ptr %p, %p3
+  %xor = xor i1 %c.1, %c.2
+  ret i1 %xor
+}
+
+declare void @foo(ptr)
+
+define i1 @inttoptr_add_ptrtoint_used_by_multiple_icmps_and_other_user(ptr %src, ptr %p2, ptr %p3) {
+; CHECK-LABEL: @inttoptr_add_ptrtoint_used_by_multiple_icmps_and_other_user(
+; CHECK-NEXT:    [[TMP1:%.*]] = ptrtoint ptr [[SRC:%.*]] to i64
+; CHECK-NEXT:    [[TMP2:%.*]] = add i64 [[TMP1]], 10
+; CHECK-NEXT:    [[P:%.*]] = inttoptr i64 [[TMP2]] to ptr
+; CHECK-NEXT:    [[C_1:%.*]] = icmp eq ptr [[P2:%.*]], [[P]]
+; CHECK-NEXT:    [[C_2:%.*]] = icmp eq ptr [[P3:%.*]], [[P]]
+; CHECK-NEXT:    [[XOR:%.*]] = xor i1 [[C_1]], [[C_2]]
+; CHECK-NEXT:    call void @foo(ptr [[P]])
+; CHECK-NEXT:    ret i1 [[XOR]]
+;
+  %i = ptrtoint ptr %src to i64
+  %a = add i64 %i, 10
+  %p = inttoptr i64 %a to ptr
+  %c.1 = icmp eq ptr %p, %p2
+  %c.2 = icmp eq ptr %p, %p3
+  %xor = xor i1 %c.1, %c.2
+  call void @foo(ptr %p)
+  ret i1 %xor
+}
+
 define i32 @h(i1 %A, i32 %B) {
 ; CHECK-LABEL: @h(
 ; CHECK-NEXT:  EntryBlock:
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..233ab328d7bbb
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/inttoptr-add-phi.ll
@@ -0,0 +1,70 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -passes=instcombine -S %s | FileCheck %s
+target datalayout = "E-p:64:64:64-p1:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
+
+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"}
+;.

fhahn added 5 commits August 14, 2025 11:27

[InstCombine] Add tests for (inttoptr (add (ptrtoint %Base), %Offset)).

1a6529d

!fixup use m_PtrToIntSameSize

8e2ac0e

[InstComb] Add tests with phi users of inttoptr.

eb8899e

fhahn requested review from nikic and dtcxzyw August 14, 2025 10:36

llvmbot added llvm:instcombine Covers the InstCombine, InstSimplify and AggressiveInstCombine passes llvm:transforms labels Aug 14, 2025

This was referenced Aug 14, 2025

[InstComb] Fold inttoptr (add (ptrtoint %B), %O) -> GEP for ICMP users. #153421

Open

[libc++] Optimize num_get integral functions #121795

Open

dtcxzyw mentioned this pull request Aug 15, 2025

Task submission dtcxzyw/llvm-opt-benchmark#1312

Open

zyw-bot mentioned this pull request Aug 15, 2025

pre-commit: PR153566 dtcxzyw/llvm-opt-benchmark#2675

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[InstComb] Allow more user for (add (ptrtoint %B), %O) to GEP transform. #153566

[InstComb] Allow more user for (add (ptrtoint %B), %O) to GEP transform. #153566

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[InstComb] Allow more user for (add (ptrtoint %B), %O) to GEP transform. #153566

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[InstComb] Allow more user for (add (ptrtoint %B), %O) to GEP transform. #153566

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