[PATCH] D75892: [InstSimplify][SVE] Fix SimplifyGEPInst for scalable vector.

[Huihui Zhang via Phabricator via llvm-commits]

huihuiz created this revision.
huihuiz added reviewers: sdesmalen, efriedma, spatel, apazos.
huihuiz added a project: LLVM.
Herald added subscribers: psnobl, rkruppe, hiraditya, tschuett.
huihuiz added a comment.

take test.ll, run: opt -S -instsimplify test.ll -o -

  define <vscale x 4 x <vscale x 4 x i32>*> @getelementptr_2() {
    %ptr = getelementptr <vscale x 4 x i32>, <vscale x 4 x i32>* null, <vscale x 4 x i64> undef
    ret <vscale x 4 x <vscale x 4 x i32>*> %ptr
  }

current upstream crash at: llvm/include/llvm/Support/TypeSize.h:126: uint64_t llvm::TypeSize::getFixedSize() const: Assertion `!IsScalable && "Request for a fixed size on a scalable object"' failed.

This patch depends on D74386 <https://reviews.llvm.org/D74386>, otherwise we get another crash at: llvm/lib/IR/Value.cpp:408: void llvm::Value::doRAUW(llvm::Value *, llvm::Value::ReplaceMetadataUses): Assertion `New->getType() == getType() && "replaceAllUses of value with new value of different type!"' failed.


Skip folds that rely on DataLayout::getTypeAllocSize(). For scalable
vector, only minimal type alloc size is known at compile-time.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D75892

Files:
  llvm/lib/Analysis/InstructionSimplify.cpp
  llvm/test/Transforms/InstSimplify/vscale.ll


Index: llvm/test/Transforms/InstSimplify/vscale.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/InstSimplify/vscale.ll
@@ -0,0 +1,23 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -instsimplify -verify < %s | FileCheck %s
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Memory Access and Addressing Operations
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+define <vscale x 4 x i32*> @getelementptr_1() {
+; CHECK-LABEL: @getelementptr_1(
+; CHECK-NEXT:    ret <vscale x 4 x i32*> zeroinitializer
+;
+  %ptr = getelementptr i32, <vscale x 4 x i32*> zeroinitializer, <vscale x 4 x i64> undef
+  ret <vscale x 4 x i32*> %ptr
+}
+
+define <vscale x 4 x <vscale x 4 x i32>*> @getelementptr_2() {
+; CHECK-LABEL: @getelementptr_2(
+; CHECK-NEXT:    ret <vscale x 4 x <vscale x 4 x i32>*> zeroinitializer
+;
+  %ptr = getelementptr <vscale x 4 x i32>, <vscale x 4 x i32>* null, <vscale x 4 x i64> undef
+  ret <vscale x 4 x <vscale x 4 x i32>*> %ptr
+}
+
Index: llvm/lib/Analysis/InstructionSimplify.cpp
===================================================================
--- llvm/lib/Analysis/InstructionSimplify.cpp
+++ llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4081,13 +4081,16 @@
   if (isa<UndefValue>(Ops[0]))
     return UndefValue::get(GEPTy);
 
+  bool IsScalableVec =
+      SrcTy->isVectorTy() ? SrcTy->getVectorIsScalable() : false;
+
   if (Ops.size() == 2) {
     // getelementptr P, 0 -> P.
     if (match(Ops[1], m_Zero()) && Ops[0]->getType() == GEPTy)
       return Ops[0];
 
     Type *Ty = SrcTy;
-    if (Ty->isSized()) {
+    if (!IsScalableVec && Ty->isSized()) {
       Value *P;
       uint64_t C;
       uint64_t TyAllocSize = Q.DL.getTypeAllocSize(Ty);
@@ -4135,7 +4138,7 @@
     }
   }
 
-  if (Q.DL.getTypeAllocSize(LastType) == 1 &&
+  if (!IsScalableVec && Q.DL.getTypeAllocSize(LastType) == 1 &&
       all_of(Ops.slice(1).drop_back(1),
              [](Value *Idx) { return match(Idx, m_Zero()); })) {
     unsigned IdxWidth =


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D75892.249276.patch
Type: text/x-patch
Size: 2144 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200310/8779c769/attachment.bin>