[llvm] r200593 - Don't put non-static allocas in the static alloca map

[Reid Kleckner]

Author: rnk
Date: Fri Jan 31 17:45:12 2014
New Revision: 200593

URL: http://llvm.org/viewvc/llvm-project?rev=200593&view=rev
Log:
Don't put non-static allocas in the static alloca map

Allocas marked inalloca are never static, but we were trying to put them
into the static alloca map if they were in the entry block.  Also add an
assertion in x86 fastisel.

Added:
    llvm/trunk/test/CodeGen/X86/dynamic-alloca-in-entry.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
    llvm/trunk/lib/Target/X86/X86FastISel.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp?rev=200593&r1=200592&r2=200593&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp Fri Jan 31 17:45:12 2014
@@ -74,7 +74,12 @@ void FunctionLoweringInfo::set(const Fun
   // them.
   Function::const_iterator BB = Fn->begin(), EB = Fn->end();
   for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I)
-    if (const AllocaInst *AI = dyn_cast<AllocaInst>(I))
+    if (const AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
+      // Don't fold inalloca allocas or other dynamic allocas into the initial
+      // stack frame allocation, even if they are in the entry block.
+      if (!AI->isStaticAlloca())
+        continue;
+
       if (const ConstantInt *CUI = dyn_cast<ConstantInt>(AI->getArraySize())) {
         Type *Ty = AI->getAllocatedType();
         uint64_t TySize = TLI->getDataLayout()->getTypeAllocSize(Ty);
@@ -88,6 +93,7 @@ void FunctionLoweringInfo::set(const Fun
         StaticAllocaMap[AI] =
           MF->getFrameInfo()->CreateStackObject(TySize, Align, false, AI);
       }
+    }
 
   for (; BB != EB; ++BB)
     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();

Modified: llvm/trunk/lib/Target/X86/X86FastISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86FastISel.cpp?rev=200593&r1=200592&r2=200593&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86FastISel.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86FastISel.cpp Fri Jan 31 17:45:12 2014
@@ -2483,6 +2483,7 @@ unsigned X86FastISel::TargetMaterializeA
   // X86SelectAddrss, and TargetMaterializeAlloca.
   if (!FuncInfo.StaticAllocaMap.count(C))
     return 0;
+  assert(C->isStaticAlloca() && "dynamic alloca in the static alloca map?");
 
   X86AddressMode AM;
   if (!X86SelectAddress(C, AM))

Added: llvm/trunk/test/CodeGen/X86/dynamic-alloca-in-entry.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/dynamic-alloca-in-entry.ll?rev=200593&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/dynamic-alloca-in-entry.ll (added)
+++ llvm/trunk/test/CodeGen/X86/dynamic-alloca-in-entry.ll Fri Jan 31 17:45:12 2014
@@ -0,0 +1,19 @@
+; RUN: llc < %s -mtriple=i686-pc-win32 | FileCheck %s
+
+; Allocas with unknown size in the entry block are dynamic.
+define void @foo(i32 %n) {
+  %m = alloca i32, i32 %n
+  ret void
+}
+; CHECK-LABEL: _foo:
+; CHECK: calll __chkstk
+; CHECK: retl
+
+; Use of inalloca implies that that the alloca is not static.
+define void @bar() {
+  %m = alloca i32, inalloca
+  ret void
+}
+; CHECK-LABEL: _bar:
+; CHECK: calll __chkstk
+; CHECK: retl