Ignore dbg intrinsics while propagating conditional expression info. Take 2.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63898 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Devang Patel 2009-02-05 23:32:52 +00:00
parent 54801f78b1
commit 32d9701d68
2 changed files with 62 additions and 6 deletions

View File

@ -17,6 +17,7 @@
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/Instructions.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/Pass.h"
#include "llvm/Type.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
@ -134,8 +135,8 @@ void CondProp::SimplifyBlock(BasicBlock *BB) {
// jump directly to the destination instead of going through this block.
void CondProp::SimplifyPredecessors(BranchInst *BI) {
// TODO: We currently only handle the most trival case, where the PHI node has
// one use (the branch), and is the only instruction besides the branch in the
// block.
// one use (the branch), and is the only instruction besides the branch and dbg
// intrinsics in the block.
PHINode *PN = cast<PHINode>(BI->getCondition());
if (PN->getNumIncomingValues() == 1) {
@ -148,7 +149,12 @@ void CondProp::SimplifyPredecessors(BranchInst *BI) {
if (!PN->hasOneUse()) return;
BasicBlock *BB = BI->getParent();
if (&*BB->begin() != PN || &*next(BB->begin()) != BI)
if (&*BB->begin() != PN)
return;
BasicBlock::iterator BBI = BB->begin();
BasicBlock::iterator BBE = BB->end();
while (BBI != BBE && isa<DbgInfoIntrinsic>(++BBI));
if (&*BBI != BI)
return;
// Ok, we have this really simple case, walk the PHI operands, looking for
@ -176,13 +182,18 @@ void CondProp::SimplifyPredecessors(BranchInst *BI) {
// the destination instead of going through this block.
void CondProp::SimplifyPredecessors(SwitchInst *SI) {
// TODO: We currently only handle the most trival case, where the PHI node has
// one use (the branch), and is the only instruction besides the branch in the
// block.
// one use (the branch), and is the only instruction besides the branch and
// dbg intrinsics in the block.
PHINode *PN = cast<PHINode>(SI->getCondition());
if (!PN->hasOneUse()) return;
BasicBlock *BB = SI->getParent();
if (&*BB->begin() != PN || &*next(BB->begin()) != SI)
if (&*BB->begin() != PN)
return;
BasicBlock::iterator BBI = BB->begin();
BasicBlock::iterator BBE = BB->end();
while (BBI != BBE && isa<DbgInfoIntrinsic>(++BBI));
if (&*BBI != SI)
return;
bool RemovedPreds = false;

View File

@ -0,0 +1,45 @@
; RUN: llvm-as < %s | opt -condprop | llvm-dis | \
; RUN: not grep {br label}
%llvm.dbg.anchor.type = type { i32, i32 }
%llvm.dbg.compile_unit.type = type { i32, { }*, i32, i8*, i8*, i8*, i1, i1, i8* }
@llvm.dbg.compile_units = linkonce constant %llvm.dbg.anchor.type { i32 458752, i32 17 }, section "llvm.metadata" ;
@.str = internal constant [4 x i8] c"a.c\00", section "llvm.metadata" ; <[4 x i8]*> [#uses=1]
@.str1 = internal constant [6 x i8] c"/tmp/\00", section "llvm.metadata" ; <[6 x i8]*> [#uses=1]
@.str2 = internal constant [55 x i8] c"4.2.1 (Based on Apple Inc. build 5636) (LLVM build 00)\00", section "llvm.metadata" ; <[55 x i8]*> [#uses=1]
@llvm.dbg.compile_unit = internal constant %llvm.dbg.compile_unit.type { i32 458769, { }* bitcast (%llvm.dbg.anchor.type* @llvm.dbg.compile_units to { }*), i32 1, i8* getelementptr ([4 x i8]* @.str, i32 0, i32 0), i8* getelementptr ([6 x i8]* @.str1, i32 0, i32 0), i8* getelementptr ([55 x i8]* @.str2, i32 0, i32 0), i1 true, i1 false, i8* null }, section "llvm.metadata" ; <%llvm.dbg.compile_unit.type*> [#uses=1]
declare void @llvm.dbg.stoppoint(i32, i32, { }*) nounwind
define i32 @test(i1 %C) {
br i1 %C, label %T1, label %F1
T1: ; preds = %0
call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
br label %Cont
F1: ; preds = %0
call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
br label %Cont
Cont: ; preds = %F1, %T1
%C2 = phi i1 [ false, %F1 ], [ true, %T1 ] ; <i1> [#uses=1]
call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
br i1 %C2, label %T2, label %F2
T2: ; preds = %Cont
call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
call void @bar( )
call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
ret i32 17
F2: ; preds = %Cont
call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
ret i32 1
}
declare void @bar()