[PATCH] D28565: Teach isAllocSiteRemovable to look through addrspacecasts

[Artur Pilipenko via Phabricator via llvm-commits]

apilipenko created this revision.
apilipenko added reviewers: nlopes, hfinkel, reames.
apilipenko added a subscriber: llvm-commits.

https://reviews.llvm.org/D28565

Files:
  lib/Transforms/InstCombine/InstructionCombining.cpp
  test/Transforms/InstCombine/alloca.ll


Index: test/Transforms/InstCombine/alloca.ll
===================================================================
--- test/Transforms/InstCombine/alloca.ll
+++ test/Transforms/InstCombine/alloca.ll
@@ -51,8 +51,8 @@
   ret i32* %A
 }
 
-; Allocas which are only used by GEPs, bitcasts, and stores (transitively)
-; should be deleted.
+; Allocas which are only used by GEPs, bitcasts, addrspacecasts, and stores
+; (transitively) should be deleted.
 define void @test5() {
 ; CHECK-LABEL: @test5(
 ; CHECK-NOT: alloca
@@ -62,6 +62,7 @@
 entry:
   %a = alloca { i32 }
   %b = alloca i32*
+  %c = alloca i32
   %a.1 = getelementptr { i32 }, { i32 }* %a, i32 0, i32 0
   store i32 123, i32* %a.1
   store i32* %a.1, i32** %b
@@ -73,6 +74,8 @@
   store atomic i32 3, i32* %a.3 release, align 4
   %a.4 = getelementptr { i32 }, { i32 }* %a, i32 0, i32 0
   store atomic i32 4, i32* %a.4 seq_cst, align 4
+  %c.1 = addrspacecast i32* %c to i32 addrspace(1)*
+  store i32 123, i32 addrspace(1)* %c.1
   ret void
 }
 
Index: lib/Transforms/InstCombine/InstructionCombining.cpp
===================================================================
--- lib/Transforms/InstCombine/InstructionCombining.cpp
+++ lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1944,6 +1944,7 @@
         // Give up the moment we see something we can't handle.
         return false;
 
+      case Instruction::AddrSpaceCast:
       case Instruction::BitCast:
       case Instruction::GetElementPtr:
         Users.emplace_back(I);
@@ -2045,7 +2046,8 @@
         replaceInstUsesWith(*C,
                             ConstantInt::get(Type::getInt1Ty(C->getContext()),
                                              C->isFalseWhenEqual()));
-      } else if (isa<BitCastInst>(I) || isa<GetElementPtrInst>(I)) {
+      } else if (isa<BitCastInst>(I) || isa<GetElementPtrInst>(I) ||
+                 isa<AddrSpaceCastInst>(I)) {
         replaceInstUsesWith(*I, UndefValue::get(I->getType()));
       }
       eraseInstFromFunction(*I);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D28565.83974.patch
Type: text/x-patch
Size: 2006 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170111/a6d58b2c/attachment.bin>