[llvm-commits] [dragonegg] r94536 - /dragonegg/trunk/llvm-backend.cpp
Duncan Sands
baldrick at free.fr
Tue Jan 26 01:10:42 PST 2010
Author: baldrick
Date: Tue Jan 26 03:10:41 2010
New Revision: 94536
URL: http://llvm.org/viewvc/llvm-project?rev=94536&view=rev
Log:
Don't sanity check the size of global variables before they get their
initial value, since if the GCC type has variable size then the LLVM
variable will only have the right size after the initial value is
processed. Remove two unused global-variable processing routines while
there.
Modified:
dragonegg/trunk/llvm-backend.cpp
Modified: dragonegg/trunk/llvm-backend.cpp
URL: http://llvm.org/viewvc/llvm-project/dragonegg/trunk/llvm-backend.cpp?rev=94536&r1=94535&r2=94536&view=diff
==============================================================================
--- dragonegg/trunk/llvm-backend.cpp (original)
+++ dragonegg/trunk/llvm-backend.cpp Tue Jan 26 03:10:41 2010
@@ -271,14 +271,29 @@
return 200;
}
-// SizeOfGlobalMatchesDecl - Whether the size of the given global value
-// is the same as that of the given GCC declaration.
+// SizeOfGlobalMatchesDecl - Whether the size of the given global value is the
+// same as that of the given GCC declaration. Conservatively returns 'true' if
+// the answer is unclear.
static bool SizeOfGlobalMatchesDecl(GlobalValue *GV, tree decl) {
+ // If the GCC declaration has no size then nothing useful can be said here.
+ if (!DECL_SIZE(decl))
+ return true;
+ assert(isInt64(DECL_SIZE(decl), true) && "Global decl with variable size!");
+
const Type *Ty = GV->getType()->getElementType();
- if (!isInt64(DECL_SIZE(decl), true) || !Ty->isSized())
+ // If the LLVM type has no size then a useful comparison cannot be made.
+ if (!Ty->isSized())
return true;
+
+ // DECL_SIZE need not be a multiple of the alignment, while the LLVM size
+ // always is. Correct for this.
+ // TODO: Change getTypeSizeInBits for aggregate types so it is no longer
+ // rounded up to the alignment.
+ uint64_t gcc_size = getInt64(DECL_SIZE(decl), true);
+ const TargetData *TD = TheTarget->getTargetData();
+ unsigned Align = 8 * TD->getABITypeAlignment(Ty);
return TheTarget->getTargetData()->getTypeAllocSizeInBits(Ty) ==
- getInt64(DECL_SIZE(decl), true);
+ ((gcc_size + Align - 1) / Align) * Align;
}
#ifndef LLVM_TARGET_NAME
@@ -904,76 +919,6 @@
}
}
-/// reset_initializer_llvm - Change the initializer for a global variable.
-void reset_initializer_llvm(tree decl) {
- // If there were earlier errors we can get here when DECL_LLVM has not
- // been set. Don't crash.
- // We can also get here when DECL_LLVM has not been set for some object
- // referenced in the initializer. Don't crash then either.
- if (errorcount || sorrycount)
- return;
-
- // Get or create the global variable now.
- GlobalVariable *GV = cast<GlobalVariable>(DECL_LLVM(decl));
-
- // Visibility may also have changed.
- handleVisibility(decl, GV);
-
- // Convert the initializer over.
- Constant *Init = TreeConstantToLLVM::Convert(DECL_INITIAL(decl));
-
- // Set the initializer.
- GV->setInitializer(Init);
-}
-
-/// reset_type_and_initializer_llvm - Change the type and initializer for
-/// a global variable.
-void reset_type_and_initializer_llvm(tree decl) {
- // If there were earlier errors we can get here when DECL_LLVM has not
- // been set. Don't crash.
- // We can also get here when DECL_LLVM has not been set for some object
- // referenced in the initializer. Don't crash then either.
- if (errorcount || sorrycount)
- return;
-
- // Get or create the global variable now.
- GlobalVariable *GV = cast<GlobalVariable>(DECL_LLVM(decl));
-
- // Visibility may also have changed.
- handleVisibility(decl, GV);
-
- // Temporary to avoid infinite recursion (see comments emit_global)
- GV->setInitializer(UndefValue::get(GV->getType()->getElementType()));
-
- // Convert the initializer over.
- Constant *Init = TreeConstantToLLVM::Convert(DECL_INITIAL(decl));
-
- // If we had a forward definition that has a type that disagrees with our
- // initializer, insert a cast now. This sort of thing occurs when we have a
- // global union, and the LLVM type followed a union initializer that is
- // different from the union element used for the type.
- if (GV->getType()->getElementType() != Init->getType()) {
- GV->removeFromParent();
- GlobalVariable *NGV = new GlobalVariable(*TheModule, Init->getType(),
- GV->isConstant(),
- GV->getLinkage(), 0,
- GV->getName());
- assert(SizeOfGlobalMatchesDecl(NGV, decl) && "Global has wrong size!");
- NGV->setVisibility(GV->getVisibility());
- NGV->setSection(GV->getSection());
- NGV->setAlignment(GV->getAlignment());
- NGV->setLinkage(GV->getLinkage());
- GV->replaceAllUsesWith(TheFolder->CreateBitCast(NGV, GV->getType()));
- changeLLVMConstant(GV, NGV);
- delete GV;
- SET_DECL_LLVM(decl, NGV);
- GV = NGV;
- }
-
- // Set the initializer.
- GV->setInitializer(Init);
-}
-
/// emit_global - Emit the specified VAR_DECL or aggregate CONST_DECL to LLVM as
/// a global variable. This function implements the end of assemble_variable.
void emit_global(tree decl) {
@@ -1029,7 +974,6 @@
GV->isConstant(),
GlobalValue::ExternalLinkage, 0,
GV->getName());
- assert(SizeOfGlobalMatchesDecl(NGV, decl) && "Global has wrong size!");
GV->replaceAllUsesWith(TheFolder->CreateBitCast(NGV, GV->getType()));
changeLLVMConstant(GV, NGV);
delete GV;
@@ -1149,6 +1093,9 @@
if (TheDebugInfo)
TheDebugInfo->EmitGlobalVariable(GV, decl);
+ // Sanity check that the LLVM global has the right size.
+ assert(SizeOfGlobalMatchesDecl(GV, decl) && "Global has wrong size!");
+
// Mark the global as written so gcc doesn't waste time outputting it.
TREE_ASM_WRITTEN(decl) = 1;
@@ -1406,7 +1353,12 @@
if (TREE_CODE(decl) == VAR_DECL && DECL_THREAD_LOCAL_P(decl))
GV->setThreadLocal(true);
- assert(SizeOfGlobalMatchesDecl(GV, decl) && "Global has wrong size!");
+ // At this point the global variable is a declaration rather than a
+ // definition, so it may have the wrong size (for example, the GCC
+ // type might have variable size, in which case the size will be set
+ // later by the initial value). Do not check the size here.
+ assert(GV->isDeclaration() && "Global has unexpected initializer!");
+
return SET_DECL_LLVM(decl, GV);
}
//TODO timevar_pop(TV_LLVM_GLOBALS);
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