[llvm] [InstCombine] Fold `getelementptr inbounds null, idx -> null` (PR #130742)
Yingwei Zheng via llvm-commits
llvm-commits at lists.llvm.org
Wed Mar 12 10:05:13 PDT 2025
https://github.com/dtcxzyw updated https://github.com/llvm/llvm-project/pull/130742
>From 989938f6a2bef278d0df3d5a8b0f9f752af25800 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Tue, 11 Mar 2025 17:44:06 +0800
Subject: [PATCH 1/3] [InstCombine] Add pre-commit tests. NFC.
---
.../InstCombine/InstructionCombining.cpp | 5 +++
.../Transforms/InstCombine/getelementptr.ll | 35 +++++++++++++++++++
llvm/test/Transforms/InstCombine/sub-gep.ll | 4 +--
3 files changed, 42 insertions(+), 2 deletions(-)
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 4c14dcfb4d75f..ac5cf74dd7707 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -2910,6 +2910,11 @@ Instruction *InstCombinerImpl::visitGetElementPtrInst(GetElementPtrInst &GEP) {
SQ.getWithInstruction(&GEP)))
return replaceInstUsesWith(GEP, V);
+ // // getelementptr inbounds null, idx -> null
+ // if (auto *BaseC = dyn_cast<Constant>(PtrOp))
+ // if (GEP.isInBounds() && BaseC->isNullValue() && !NullPointerIsDefined(GEP.getFunction(), GEPType->getPointerAddressSpace()))
+ // return replaceInstUsesWith(GEP, PtrOp);
+
// For vector geps, use the generic demanded vector support.
// Skip if GEP return type is scalable. The number of elements is unknown at
// compile-time.
diff --git a/llvm/test/Transforms/InstCombine/getelementptr.ll b/llvm/test/Transforms/InstCombine/getelementptr.ll
index ec03d9a2dae2b..6755a74940ee2 100644
--- a/llvm/test/Transforms/InstCombine/getelementptr.ll
+++ b/llvm/test/Transforms/InstCombine/getelementptr.ll
@@ -2019,5 +2019,40 @@ define ptr @gep_merge_nusw_const(ptr %p, i64 %idx, i64 %idx2) {
ret ptr %gep
}
+define <2 x ptr> @gep_inbounds_null_vec(i64 %idx) {
+; CHECK-LABEL: @gep_inbounds_null_vec(
+; CHECK-NEXT: [[P:%.*]] = getelementptr inbounds i8, <2 x ptr> zeroinitializer, i64 [[IDX:%.*]]
+; CHECK-NEXT: ret <2 x ptr> [[P]]
+;
+ %p = getelementptr inbounds i8, <2 x ptr> zeroinitializer, i64 %idx
+ ret <2 x ptr> %p
+}
+
+define <2 x ptr> @gep_inbounds_null_vec_broadcast(<2 x i64> %idx) {
+; CHECK-LABEL: @gep_inbounds_null_vec_broadcast(
+; CHECK-NEXT: [[P:%.*]] = getelementptr inbounds i8, ptr null, <2 x i64> [[IDX:%.*]]
+; CHECK-NEXT: ret <2 x ptr> [[P]]
+;
+ %p = getelementptr inbounds i8, ptr null, <2 x i64> %idx
+ ret <2 x ptr> %p
+}
+
+define ptr @gep_noinbounds_null(i64 %idx) {
+; CHECK-LABEL: @gep_noinbounds_null(
+; CHECK-NEXT: [[P:%.*]] = getelementptr i8, ptr null, i64 [[IDX:%.*]]
+; CHECK-NEXT: ret ptr [[P]]
+;
+ %p = getelementptr i8, ptr null, i64 %idx
+ ret ptr %p
+}
+
+define ptr @gep_inbounds_null_null_is_valid(i64 %idx) null_pointer_is_valid {
+; CHECK-LABEL: @gep_inbounds_null_null_is_valid(
+; CHECK-NEXT: [[P:%.*]] = getelementptr inbounds i8, ptr null, i64 [[IDX:%.*]]
+; CHECK-NEXT: ret ptr [[P]]
+;
+ %p = getelementptr inbounds i8, ptr null, i64 %idx
+ ret ptr %p
+}
!0 = !{!"branch_weights", i32 2, i32 10}
diff --git a/llvm/test/Transforms/InstCombine/sub-gep.ll b/llvm/test/Transforms/InstCombine/sub-gep.ll
index 3f8728d3a4381..c86a1a37bd7ad 100644
--- a/llvm/test/Transforms/InstCombine/sub-gep.ll
+++ b/llvm/test/Transforms/InstCombine/sub-gep.ll
@@ -741,7 +741,7 @@ define i64 @nullptrtoint_scalable_c() {
; CHECK-NEXT: ret i64 [[PTR_IDX]]
;
entry:
- %ptr = getelementptr inbounds <vscale x 4 x i32>, ptr null, i64 8
+ %ptr = getelementptr nusw <vscale x 4 x i32>, ptr null, i64 8
%ret = ptrtoint ptr %ptr to i64
ret i64 %ret
}
@@ -755,7 +755,7 @@ define i64 @nullptrtoint_scalable_x(i64 %x) {
; CHECK-NEXT: ret i64 [[PTR_IDX]]
;
entry:
- %ptr = getelementptr inbounds <vscale x 4 x i32>, ptr null, i64 %x
+ %ptr = getelementptr nusw <vscale x 4 x i32>, ptr null, i64 %x
%ret = ptrtoint ptr %ptr to i64
ret i64 %ret
}
>From 63e8102a10787e156de06e84bca34f2277560170 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Tue, 11 Mar 2025 18:09:06 +0800
Subject: [PATCH 2/3] [InstCombine] Fold `getelementptr inbounds null, idx ->
null`
---
.../Transforms/InstCombine/InstructionCombining.cpp | 10 ++++++----
llvm/test/Transforms/InstCombine/getelementptr.ll | 12 ++++--------
llvm/test/Transforms/InstCombine/store.ll | 3 +--
3 files changed, 11 insertions(+), 14 deletions(-)
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index ac5cf74dd7707..dcb17ee8d7b43 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -2910,10 +2910,12 @@ Instruction *InstCombinerImpl::visitGetElementPtrInst(GetElementPtrInst &GEP) {
SQ.getWithInstruction(&GEP)))
return replaceInstUsesWith(GEP, V);
- // // getelementptr inbounds null, idx -> null
- // if (auto *BaseC = dyn_cast<Constant>(PtrOp))
- // if (GEP.isInBounds() && BaseC->isNullValue() && !NullPointerIsDefined(GEP.getFunction(), GEPType->getPointerAddressSpace()))
- // return replaceInstUsesWith(GEP, PtrOp);
+ // getelementptr inbounds null, idx -> null
+ if (auto *BaseC = dyn_cast<Constant>(PtrOp))
+ if (GEP.isInBounds() && BaseC->isNullValue() &&
+ !NullPointerIsDefined(GEP.getFunction(),
+ GEPType->getPointerAddressSpace()))
+ return replaceInstUsesWith(GEP, Constant::getNullValue(GEPType));
// For vector geps, use the generic demanded vector support.
// Skip if GEP return type is scalable. The number of elements is unknown at
diff --git a/llvm/test/Transforms/InstCombine/getelementptr.ll b/llvm/test/Transforms/InstCombine/getelementptr.ll
index 6755a74940ee2..c1bd6806eae86 100644
--- a/llvm/test/Transforms/InstCombine/getelementptr.ll
+++ b/llvm/test/Transforms/InstCombine/getelementptr.ll
@@ -1328,8 +1328,7 @@ define ptr @PR45084_extra_use(i1 %cond, ptr %p) {
define ptr @gep_null_inbounds(i64 %idx) {
; CHECK-LABEL: @gep_null_inbounds(
-; CHECK-NEXT: [[GEP:%.*]] = getelementptr inbounds i8, ptr null, i64 [[IDX:%.*]]
-; CHECK-NEXT: ret ptr [[GEP]]
+; CHECK-NEXT: ret ptr null
;
%gep = getelementptr inbounds i8, ptr null, i64 %idx
ret ptr %gep
@@ -1355,8 +1354,7 @@ define ptr @gep_null_defined(i64 %idx) null_pointer_is_valid {
define ptr @gep_null_inbounds_different_type(i64 %idx1, i64 %idx2) {
; CHECK-LABEL: @gep_null_inbounds_different_type(
-; CHECK-NEXT: [[GEP:%.*]] = getelementptr inbounds [0 x i8], ptr null, i64 0, i64 [[IDX2:%.*]]
-; CHECK-NEXT: ret ptr [[GEP]]
+; CHECK-NEXT: ret ptr null
;
%gep = getelementptr inbounds [0 x i8], ptr null, i64 %idx1, i64 %idx2
ret ptr %gep
@@ -2021,8 +2019,7 @@ define ptr @gep_merge_nusw_const(ptr %p, i64 %idx, i64 %idx2) {
define <2 x ptr> @gep_inbounds_null_vec(i64 %idx) {
; CHECK-LABEL: @gep_inbounds_null_vec(
-; CHECK-NEXT: [[P:%.*]] = getelementptr inbounds i8, <2 x ptr> zeroinitializer, i64 [[IDX:%.*]]
-; CHECK-NEXT: ret <2 x ptr> [[P]]
+; CHECK-NEXT: ret <2 x ptr> zeroinitializer
;
%p = getelementptr inbounds i8, <2 x ptr> zeroinitializer, i64 %idx
ret <2 x ptr> %p
@@ -2030,8 +2027,7 @@ define <2 x ptr> @gep_inbounds_null_vec(i64 %idx) {
define <2 x ptr> @gep_inbounds_null_vec_broadcast(<2 x i64> %idx) {
; CHECK-LABEL: @gep_inbounds_null_vec_broadcast(
-; CHECK-NEXT: [[P:%.*]] = getelementptr inbounds i8, ptr null, <2 x i64> [[IDX:%.*]]
-; CHECK-NEXT: ret <2 x ptr> [[P]]
+; CHECK-NEXT: ret <2 x ptr> zeroinitializer
;
%p = getelementptr inbounds i8, ptr null, <2 x i64> %idx
ret <2 x ptr> %p
diff --git a/llvm/test/Transforms/InstCombine/store.ll b/llvm/test/Transforms/InstCombine/store.ll
index daa40da1828b5..48c63c6f24c72 100644
--- a/llvm/test/Transforms/InstCombine/store.ll
+++ b/llvm/test/Transforms/InstCombine/store.ll
@@ -49,8 +49,7 @@ define void @test2(ptr %P) {
define void @store_at_gep_off_null_inbounds(i64 %offset) {
; CHECK-LABEL: @store_at_gep_off_null_inbounds(
-; CHECK-NEXT: [[PTR:%.*]] = getelementptr inbounds i32, ptr null, i64 [[OFFSET:%.*]]
-; CHECK-NEXT: store i32 poison, ptr [[PTR]], align 4
+; CHECK-NEXT: store i32 poison, ptr null, align 4
; CHECK-NEXT: ret void
;
%ptr = getelementptr inbounds i32, ptr null, i64 %offset
>From ee6350261a0fee30a0b8166b53ec6e3d63b4ba27 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Thu, 13 Mar 2025 01:03:46 +0800
Subject: [PATCH 3/3] [InstSimplify] Move fold into InstSimplify
---
llvm/lib/Analysis/InstructionSimplify.cpp | 8 +++
.../InstCombine/InstructionCombining.cpp | 7 --
.../MemoryDependenceAnalysis/InvariantLoad.ll | 2 +-
.../ValueTracking/gep-negative-issue.ll | 2 +-
llvm/test/CodeGen/AMDGPU/chain-hi-to-lo.ll | 2 +-
.../CodeGen/AMDGPU/memcpy-crash-issue63986.ll | 2 +-
...ector-constainsundef-crash-inseltpoison.ll | 2 +-
.../constexpr-vector-constainsundef-crash.ll | 2 +-
.../Transforms/InstCombine/getelementptr.ll | 68 -------------------
.../InstSimplify/ConstProp/cast-vector.ll | 4 +-
llvm/test/Transforms/InstSimplify/gep.ll | 59 ++++++++++++++++
11 files changed, 75 insertions(+), 83 deletions(-)
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 1c33c6bebdd1b..48259e0f7a5f1 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -5041,6 +5041,14 @@ static Value *simplifyGEPInst(Type *SrcTy, Value *Ptr,
if (Q.isUndefValue(Ptr))
return UndefValue::get(GEPTy);
+ // getelementptr inbounds null, idx -> null
+ if (NW.isInBounds() && Q.IIQ.UseInstrInfo && Q.CxtI) {
+ if (auto *BaseC = dyn_cast<Constant>(Ptr))
+ if (BaseC->isNullValue() &&
+ !NullPointerIsDefined(Q.CxtI->getFunction(), AS))
+ return Constant::getNullValue(GEPTy);
+ }
+
bool IsScalableVec =
SrcTy->isScalableTy() || any_of(Indices, [](const Value *V) {
return isa<ScalableVectorType>(V->getType());
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index dcb17ee8d7b43..4c14dcfb4d75f 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -2910,13 +2910,6 @@ Instruction *InstCombinerImpl::visitGetElementPtrInst(GetElementPtrInst &GEP) {
SQ.getWithInstruction(&GEP)))
return replaceInstUsesWith(GEP, V);
- // getelementptr inbounds null, idx -> null
- if (auto *BaseC = dyn_cast<Constant>(PtrOp))
- if (GEP.isInBounds() && BaseC->isNullValue() &&
- !NullPointerIsDefined(GEP.getFunction(),
- GEPType->getPointerAddressSpace()))
- return replaceInstUsesWith(GEP, Constant::getNullValue(GEPType));
-
// For vector geps, use the generic demanded vector support.
// Skip if GEP return type is scalable. The number of elements is unknown at
// compile-time.
diff --git a/llvm/test/Analysis/MemoryDependenceAnalysis/InvariantLoad.ll b/llvm/test/Analysis/MemoryDependenceAnalysis/InvariantLoad.ll
index 60c97b4c275a1..e49db3d8c3e8e 100644
--- a/llvm/test/Analysis/MemoryDependenceAnalysis/InvariantLoad.ll
+++ b/llvm/test/Analysis/MemoryDependenceAnalysis/InvariantLoad.ll
@@ -135,7 +135,7 @@ alive:
; This is reduced test case catching regression in the first version of the
; fix for invariant loads (https://reviews.llvm.org/D64405).
-define void @test4() {
+define void @test4() null_pointer_is_valid {
; CHECK-LABEL: @test4(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[TMP0:%.*]] = load float, ptr inttoptr (i64 8 to ptr), align 4
diff --git a/llvm/test/Analysis/ValueTracking/gep-negative-issue.ll b/llvm/test/Analysis/ValueTracking/gep-negative-issue.ll
index 98b6fa7958f0c..ede5994ce5c3b 100644
--- a/llvm/test/Analysis/ValueTracking/gep-negative-issue.ll
+++ b/llvm/test/Analysis/ValueTracking/gep-negative-issue.ll
@@ -5,7 +5,7 @@ target triple = "x86_64-unknown-linux-gnu"
%ArrayImpl = type { i64, ptr addrspace(100), [1 x i64], [1 x i64], [1 x i64], i64, i64, ptr addrspace(100), ptr addrspace(100), i8, i64 }
%_array = type { i64, ptr addrspace(100), i8 }
-define void @test(i64 %n_chpl) {
+define void @test(i64 %n_chpl) null_pointer_is_valid {
entry:
; First section is some code
%0 = getelementptr inbounds %_array, ptr null, i32 0, i32 1
diff --git a/llvm/test/CodeGen/AMDGPU/chain-hi-to-lo.ll b/llvm/test/CodeGen/AMDGPU/chain-hi-to-lo.ll
index b6eca494fe690..5d704dd82f7a4 100644
--- a/llvm/test/CodeGen/AMDGPU/chain-hi-to-lo.ll
+++ b/llvm/test/CodeGen/AMDGPU/chain-hi-to-lo.ll
@@ -383,7 +383,7 @@ bb:
ret <2 x half> %result
}
-define <2 x half> @chain_hi_to_lo_flat() {
+define <2 x half> @chain_hi_to_lo_flat() null_pointer_is_valid {
; GCN-LABEL: chain_hi_to_lo_flat:
; GCN: ; %bb.0: ; %bb
; GCN-NEXT: s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
diff --git a/llvm/test/CodeGen/AMDGPU/memcpy-crash-issue63986.ll b/llvm/test/CodeGen/AMDGPU/memcpy-crash-issue63986.ll
index 8157b1a7f7c80..18055121e3d5f 100644
--- a/llvm/test/CodeGen/AMDGPU/memcpy-crash-issue63986.ll
+++ b/llvm/test/CodeGen/AMDGPU/memcpy-crash-issue63986.ll
@@ -3,7 +3,7 @@
%"struct.__llvm_libc::rpc::Buffer" = type { [8 x i64] }
-define void @issue63986(i64 %0, i64 %idxprom) {
+define void @issue63986(i64 %0, i64 %idxprom) null_pointer_is_valid {
; CHECK-LABEL: issue63986:
; CHECK: ; %bb.0: ; %entry
; CHECK-NEXT: s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
diff --git a/llvm/test/Transforms/GVN/constexpr-vector-constainsundef-crash-inseltpoison.ll b/llvm/test/Transforms/GVN/constexpr-vector-constainsundef-crash-inseltpoison.ll
index a40811aa1dde1..b1db5b0314ac6 100644
--- a/llvm/test/Transforms/GVN/constexpr-vector-constainsundef-crash-inseltpoison.ll
+++ b/llvm/test/Transforms/GVN/constexpr-vector-constainsundef-crash-inseltpoison.ll
@@ -5,7 +5,7 @@
; https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=24278
; Make sure we do not crash when dealing with a vector constant expression.
-define <4 x ptr> @test(ptr %ptr) {
+define <4 x ptr> @test(ptr %ptr) null_pointer_is_valid {
; CHECK-LABEL: @test(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[L3:%.*]] = load i64, ptr [[PTR:%.*]], align 4
diff --git a/llvm/test/Transforms/GVN/constexpr-vector-constainsundef-crash.ll b/llvm/test/Transforms/GVN/constexpr-vector-constainsundef-crash.ll
index ddb223fffab5e..f676e81c114e8 100644
--- a/llvm/test/Transforms/GVN/constexpr-vector-constainsundef-crash.ll
+++ b/llvm/test/Transforms/GVN/constexpr-vector-constainsundef-crash.ll
@@ -5,7 +5,7 @@
; https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=24278
; Make sure we do not crash when dealing with a vector constant expression.
-define <4 x ptr> @test(ptr %ptr) {
+define <4 x ptr> @test(ptr %ptr) null_pointer_is_valid {
; CHECK-LABEL: @test(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[L3:%.*]] = load i64, ptr [[PTR:%.*]], align 4
diff --git a/llvm/test/Transforms/InstCombine/getelementptr.ll b/llvm/test/Transforms/InstCombine/getelementptr.ll
index c1bd6806eae86..feba952919b9a 100644
--- a/llvm/test/Transforms/InstCombine/getelementptr.ll
+++ b/llvm/test/Transforms/InstCombine/getelementptr.ll
@@ -1326,40 +1326,6 @@ define ptr @PR45084_extra_use(i1 %cond, ptr %p) {
ret ptr %sel
}
-define ptr @gep_null_inbounds(i64 %idx) {
-; CHECK-LABEL: @gep_null_inbounds(
-; CHECK-NEXT: ret ptr null
-;
- %gep = getelementptr inbounds i8, ptr null, i64 %idx
- ret ptr %gep
-}
-
-define ptr @gep_null_not_inbounds(i64 %idx) {
-; CHECK-LABEL: @gep_null_not_inbounds(
-; CHECK-NEXT: [[GEP:%.*]] = getelementptr i8, ptr null, i64 [[IDX:%.*]]
-; CHECK-NEXT: ret ptr [[GEP]]
-;
- %gep = getelementptr i8, ptr null, i64 %idx
- ret ptr %gep
-}
-
-define ptr @gep_null_defined(i64 %idx) null_pointer_is_valid {
-; CHECK-LABEL: @gep_null_defined(
-; CHECK-NEXT: [[GEP:%.*]] = getelementptr inbounds i8, ptr null, i64 [[IDX:%.*]]
-; CHECK-NEXT: ret ptr [[GEP]]
-;
- %gep = getelementptr inbounds i8, ptr null, i64 %idx
- ret ptr %gep
-}
-
-define ptr @gep_null_inbounds_different_type(i64 %idx1, i64 %idx2) {
-; CHECK-LABEL: @gep_null_inbounds_different_type(
-; CHECK-NEXT: ret ptr null
-;
- %gep = getelementptr inbounds [0 x i8], ptr null, i64 %idx1, i64 %idx2
- ret ptr %gep
-}
-
define ptr @D98588(ptr %c1, i64 %offset) {
; CHECK-LABEL: @D98588(
; CHECK-NEXT: [[C2_NEXT_IDX:%.*]] = shl nsw i64 [[OFFSET:%.*]], 3
@@ -2017,38 +1983,4 @@ define ptr @gep_merge_nusw_const(ptr %p, i64 %idx, i64 %idx2) {
ret ptr %gep
}
-define <2 x ptr> @gep_inbounds_null_vec(i64 %idx) {
-; CHECK-LABEL: @gep_inbounds_null_vec(
-; CHECK-NEXT: ret <2 x ptr> zeroinitializer
-;
- %p = getelementptr inbounds i8, <2 x ptr> zeroinitializer, i64 %idx
- ret <2 x ptr> %p
-}
-
-define <2 x ptr> @gep_inbounds_null_vec_broadcast(<2 x i64> %idx) {
-; CHECK-LABEL: @gep_inbounds_null_vec_broadcast(
-; CHECK-NEXT: ret <2 x ptr> zeroinitializer
-;
- %p = getelementptr inbounds i8, ptr null, <2 x i64> %idx
- ret <2 x ptr> %p
-}
-
-define ptr @gep_noinbounds_null(i64 %idx) {
-; CHECK-LABEL: @gep_noinbounds_null(
-; CHECK-NEXT: [[P:%.*]] = getelementptr i8, ptr null, i64 [[IDX:%.*]]
-; CHECK-NEXT: ret ptr [[P]]
-;
- %p = getelementptr i8, ptr null, i64 %idx
- ret ptr %p
-}
-
-define ptr @gep_inbounds_null_null_is_valid(i64 %idx) null_pointer_is_valid {
-; CHECK-LABEL: @gep_inbounds_null_null_is_valid(
-; CHECK-NEXT: [[P:%.*]] = getelementptr inbounds i8, ptr null, i64 [[IDX:%.*]]
-; CHECK-NEXT: ret ptr [[P]]
-;
- %p = getelementptr inbounds i8, ptr null, i64 %idx
- ret ptr %p
-}
-
!0 = !{!"branch_weights", i32 2, i32 10}
diff --git a/llvm/test/Transforms/InstSimplify/ConstProp/cast-vector.ll b/llvm/test/Transforms/InstSimplify/ConstProp/cast-vector.ll
index 3e4504a166366..da95bfa97d5a7 100644
--- a/llvm/test/Transforms/InstSimplify/ConstProp/cast-vector.ll
+++ b/llvm/test/Transforms/InstSimplify/ConstProp/cast-vector.ll
@@ -5,7 +5,7 @@
; "offsetof-like expression" case).
; This used to hit an assert due to not supporting vectors in
; llvm::ConstantFoldCastInstruction when handling ptrtoint.
-define <2 x i16> @test1() {
+define <2 x i16> @test1() null_pointer_is_valid {
; CHECK-LABEL: @test1(
; CHECK-NEXT: entry:
; CHECK-NEXT: ret <2 x i16> ptrtoint (<2 x ptr> getelementptr inbounds ([10 x i32], ptr null, <2 x i64> zeroinitializer, <2 x i64> <i64 5, i64 7>) to <2 x i16>)
@@ -20,7 +20,7 @@ entry:
; "sizeof-like expression" case).
; This used to hit an assert due to not supporting vectors in
; llvm::ConstantFoldCastInstruction when handling ptrtoint.
-define <2 x i16> @test2() {
+define <2 x i16> @test2() null_pointer_is_valid {
; CHECK-LABEL: @test2(
; CHECK-NEXT: entry:
; CHECK-NEXT: ret <2 x i16> ptrtoint (<2 x ptr> getelementptr (i32, ptr null, <2 x i64> <i64 5, i64 7>) to <2 x i16>)
diff --git a/llvm/test/Transforms/InstSimplify/gep.ll b/llvm/test/Transforms/InstSimplify/gep.ll
index a330f5cbc9268..a73c902fac647 100644
--- a/llvm/test/Transforms/InstSimplify/gep.ll
+++ b/llvm/test/Transforms/InstSimplify/gep.ll
@@ -386,3 +386,62 @@ define i64 @gep_array_of_scalable_vectors_ptrdiff(ptr %ptr) {
%diff = sub i64 %c2.int, %c1.int
ret i64 %diff
}
+
+define ptr @gep_null_inbounds(i64 %idx) {
+; CHECK-LABEL: @gep_null_inbounds(
+; CHECK-NEXT: ret ptr null
+;
+ %gep = getelementptr inbounds i8, ptr null, i64 %idx
+ ret ptr %gep
+}
+
+define ptr @gep_null_not_inbounds(i64 %idx) {
+; CHECK-LABEL: @gep_null_not_inbounds(
+; CHECK-NEXT: [[GEP:%.*]] = getelementptr i8, ptr null, i64 [[IDX:%.*]]
+; CHECK-NEXT: ret ptr [[GEP]]
+;
+ %gep = getelementptr i8, ptr null, i64 %idx
+ ret ptr %gep
+}
+
+define ptr @gep_null_defined(i64 %idx) null_pointer_is_valid {
+; CHECK-LABEL: @gep_null_defined(
+; CHECK-NEXT: [[GEP:%.*]] = getelementptr inbounds i8, ptr null, i64 [[IDX:%.*]]
+; CHECK-NEXT: ret ptr [[GEP]]
+;
+ %gep = getelementptr inbounds i8, ptr null, i64 %idx
+ ret ptr %gep
+}
+
+define ptr @gep_null_inbounds_different_type(i64 %idx1, i64 %idx2) {
+; CHECK-LABEL: @gep_null_inbounds_different_type(
+; CHECK-NEXT: ret ptr null
+;
+ %gep = getelementptr inbounds [0 x i8], ptr null, i64 %idx1, i64 %idx2
+ ret ptr %gep
+}
+
+define <2 x ptr> @gep_inbounds_null_vec(i64 %idx) {
+; CHECK-LABEL: @gep_inbounds_null_vec(
+; CHECK-NEXT: ret <2 x ptr> zeroinitializer
+;
+ %p = getelementptr inbounds i8, <2 x ptr> zeroinitializer, i64 %idx
+ ret <2 x ptr> %p
+}
+
+define <2 x ptr> @gep_inbounds_null_vec_broadcast(<2 x i64> %idx) {
+; CHECK-LABEL: @gep_inbounds_null_vec_broadcast(
+; CHECK-NEXT: ret <2 x ptr> zeroinitializer
+;
+ %p = getelementptr inbounds i8, ptr null, <2 x i64> %idx
+ ret <2 x ptr> %p
+}
+
+define ptr @gep_noinbounds_null(i64 %idx) {
+; CHECK-LABEL: @gep_noinbounds_null(
+; CHECK-NEXT: [[P:%.*]] = getelementptr i8, ptr null, i64 [[IDX:%.*]]
+; CHECK-NEXT: ret ptr [[P]]
+;
+ %p = getelementptr i8, ptr null, i64 %idx
+ ret ptr %p
+}
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