6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-07-21 18:29:45 +00:00
Code Issues Projects Releases Wiki Activity

1. modernize the constantmerge pass, using densemap/smallvector.

Browse Source 
2. don't bother trying to merge globals in non-default sections,
   doing so is quite dubious at best anyway.
3. fix a bug reported by Arnaud de Grandmaison where we'd try to
   merge two globals in different address spaces.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95995 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2010-02-12 18:17:23 +00:00
parent 4b2657a404
commit c3b6ffc431
2 changed files with 44 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
lib/Transforms/IPO/ConstantMerge.cpp
View File

@ -19,10 +19,11 @@
#define DEBUG_TYPE "constmerge"
#include "llvm/Transforms/IPO.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/Pass.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/Statistic.h"
#include <map>
using namespace llvm;
STATISTIC(NumMerged, "Number of global constants merged");
@ -48,10 +49,10 @@ ModulePass *llvm::createConstantMergePass() { return new ConstantMerge(); }
bool ConstantMerge::runOnModule(Module &M) {
// Map unique constant/section pairs to globals. We don't want to merge
// globals in different sections.
std::map<std::pair<Constant*, std::string>, GlobalVariable*> CMap;
DenseMap<Constant*, GlobalVariable*> CMap;
// Replacements - This vector contains a list of replacements to perform.
std::vector<std::pair<GlobalVariable*, GlobalVariable*> > Replacements;
SmallVector<std::pair<GlobalVariable*, GlobalVariable*>, 32> Replacements;
bool MadeChange = false;
@ -76,19 +77,21 @@ bool ConstantMerge::runOnModule(Module &M) {
continue;
}
// Only process constants with initializers.
if (GV->isConstant() && GV->hasDefinitiveInitializer()) {
Constant *Init = GV->getInitializer();
// Only process constants with initializers in the default addres space.
if (!GV->isConstant() ||!GV->hasDefinitiveInitializer() ||
GV->getType()->getAddressSpace() != 0 || !GV->getSection().empty())
continue;
Constant *Init = GV->getInitializer();
// Check to see if the initializer is already known.
GlobalVariable *&Slot = CMap[std::make_pair(Init, GV->getSection())];
// Check to see if the initializer is already known.
GlobalVariable *&Slot = CMap[Init];
if (Slot == 0) { // Nope, add it to the map.
Slot = GV;
} else if (GV->hasLocalLinkage()) { // Yup, this is a duplicate!
// Make all uses of the duplicate constant use the canonical version.
Replacements.push_back(std::make_pair(GV, Slot));
}
if (Slot == 0) { // Nope, add it to the map.
Slot = GV;
} else if (GV->hasLocalLinkage()) { // Yup, this is a duplicate!
// Make all uses of the duplicate constant use the canonical version.
Replacements.push_back(std::make_pair(GV, Slot));
}
}
@ -100,11 +103,11 @@ bool ConstantMerge::runOnModule(Module &M) {
// now. This avoid invalidating the pointers in CMap, which are unneeded
// now.
for (unsigned i = 0, e = Replacements.size(); i != e; ++i) {
// Eliminate any uses of the dead global...
// Eliminate any uses of the dead global.
Replacements[i].first->replaceAllUsesWith(Replacements[i].second);
// Delete the global value from the module...
M.getGlobalList().erase(Replacements[i].first);
// Delete the global value from the module.
Replacements[i].first->eraseFromParent();
}
NumMerged += Replacements.size();

34
test/Transforms/ConstantMerge/dont-merge.ll
View File

@ -1,16 +1,30 @@
; RUN: opt < %s -constmerge -S | grep foo
; RUN: opt < %s -constmerge -S | grep bar
; RUN: opt < %s -constmerge -S | FileCheck %s
; Don't merge constants in different sections.
; Don't merge constants with specified sections.
@G1 = internal constant i32 1, section "foo" ; <i32*> [#uses=1]
@G2 = internal constant i32 1, section "bar" ; <i32*> [#uses=1]
@G3 = internal constant i32 1, section "bar" ; <i32*> [#uses=1]
@T1G1 = internal constant i32 1, section "foo"
@T1G2 = internal constant i32 1, section "bar"
@T1G3 = internal constant i32 1, section "bar"
define void @test(i32** %P1, i32** %P2, i32** %P3) {
store i32* @G1, i32** %P1
store i32* @G2, i32** %P2
store i32* @G3, i32** %P3
; CHECK: @T1G1
; CHECK: @T1G2
; CHECK: @T1G3
define void @test1(i32** %P1, i32** %P2, i32** %P3) {
store i32* @T1G1, i32** %P1
store i32* @T1G2, i32** %P2
store i32* @T1G3, i32** %P3
ret void
}
@T2a = internal constant i32 224
@T2b = internal addrspace(30) constant i32 224
; CHECK: @T2a
; CHECK: @T2b
define void @test2(i32** %P1, i32 addrspace(30)** %P2) {
store i32* @T2a, i32** %P1
store i32 addrspace(30)* @T2b, i32 addrspace(30)** %P2
ret void
}