6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-12 02:33:33 +00:00
Code Issues Projects Releases Wiki Activity

Record landing pads with a SmallSetVector to avoid multiple entries.

Browse Source 
There may be many invokes that share one landing pad, and the previous code
would record the landing pad once for each invoke.  Besides the wasted
effort, a pair of volatile loads gets inserted every time the landing pad is
processed.  The rest of the code can get optimized away when a landing pad
is processed repeatedly, but the volatile loads remain, resulting in code like:

LBB35_18:
Ltmp483:
        ldr     r2, [r7, #-72]
        ldr     r2, [r7, #-68]
        ldr     r2, [r7, #-72]
        ldr     r2, [r7, #-68]
        ldr     r2, [r7, #-72]
        ldr     r2, [r7, #-68]
        ldr     r2, [r7, #-72]
        ldr     r2, [r7, #-68]
        ldr     r2, [r7, #-72]
        ldr     r2, [r7, #-68]
        ldr     r2, [r7, #-72]
        ldr     r2, [r7, #-68]
        ldr     r2, [r7, #-72]
        ldr     r2, [r7, #-68]
        ldr     r2, [r7, #-72]
        ldr     r2, [r7, #-68]
        ldr     r4, [r7, #-72]
        ldr     r2, [r7, #-68]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144787 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bob Wilson 2011-11-16 07:57:21 +00:00
parent 12755b07ab
commit f1b41dd38d
1 changed files with 5 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
lib/CodeGen/SjLjEHPrepare.cpp
View File

@ -30,6 +30,7 @@
#include "llvm/Support/Debug.h"
#include "llvm/Support/IRBuilder.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
@ -364,13 +365,13 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F,
bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) {
SmallVector<ReturnInst*, 16> Returns;
SmallVector<InvokeInst*, 16> Invokes;
SmallVector<LandingPadInst*, 16> LPads;
SmallSetVector<LandingPadInst*, 16> LPads;
// Look through the terminators of the basic blocks to find invokes.
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
Invokes.push_back(II);
LPads.push_back(II->getUnwindDest()->getLandingPadInst());
LPads.insert(II->getUnwindDest()->getLandingPadInst());
} else if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
Returns.push_back(RI);
}
@ -382,7 +383,8 @@ bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) {
lowerIncomingArguments(F);
lowerAcrossUnwindEdges(F, Invokes);
Value *FuncCtx = setupFunctionContext(F, LPads);
Value *FuncCtx =
setupFunctionContext(F, makeArrayRef(LPads.begin(), LPads.end()));
BasicBlock *EntryBB = F.begin();
Type *Int32Ty = Type::getInt32Ty(F.getContext());