6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-13 04:30:23 +00:00
Code Issues Projects Releases Wiki Activity

Fixes PR 1200

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34359 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dale Johannesen 2007-02-17 00:44:34 +00:00
parent affeb56480
commit 6b896cec8b
4 changed files with 103 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
lib/CodeGen/BranchFolding.cpp
View File

@ -431,6 +431,9 @@ bool BranchFolder::TailMergeBlocks(MachineFunction &MF) {
bool BranchFolder::OptimizeBranches(MachineFunction &MF) {
MadeChange = false;
// Make sure blocks are numbered in order
MF.RenumberBlocks();
for (MachineFunction::iterator I = ++MF.begin(), E = MF.end(); I != E; ) {
MachineBasicBlock *MBB = I++;
OptimizeBlock(MBB);
@ -849,22 +852,35 @@ void BranchFolder::OptimizeBlock(MachineBasicBlock *MBB) {
PriorTBB, PriorFBB, PriorCond)) {
// Now we know that there was no fall-through into this block, check to
// see if it has a fall-through into its successor.
if (!CanFallThrough(MBB, CurUnAnalyzable, CurTBB, CurFBB, CurCond)) {
// Check all the predecessors of this block. If one of them has no fall
// throughs, move this block right after it.
for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
E = MBB->pred_end(); PI != E; ++PI) {
// Analyze the branch at the end of the pred.
MachineBasicBlock *PredBB = *PI;
MachineFunction::iterator PredFallthrough = PredBB; ++PredFallthrough;
std::vector<MachineOperand> PredCond;
if (PredBB != MBB && !CanFallThrough(PredBB)) {
MBB->moveAfter(PredBB);
MadeChange = true;
return OptimizeBlock(MBB);
bool CurFallsThru = CanFallThrough(MBB, CurUnAnalyzable, CurTBB, CurFBB,
CurCond);
// Check all the predecessors of this block. If one of them has no fall
// throughs, move this block right after it.
for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
E = MBB->pred_end(); PI != E; ++PI) {
// Analyze the branch at the end of the pred.
MachineBasicBlock *PredBB = *PI;
MachineFunction::iterator PredFallthrough = PredBB; ++PredFallthrough;
if (PredBB != MBB && !CanFallThrough(PredBB)
&& (!CurFallsThru || MBB->getNumber() >= PredBB->getNumber())) {
// If the current block doesn't fall through, just move it.
// If the current block can fall through and does not end with a
// conditional branch, we need to append an unconditional jump to
// the (current) next block. To avoid a possible compile-time
// infinite loop, move blocks only backward in this case.
if (CurFallsThru) {
MachineBasicBlock *NextBB = next(MachineFunction::iterator(MBB));
CurCond.clear();
TII->InsertBranch(*MBB, NextBB, 0, CurCond);
}
MBB->moveAfter(PredBB);
MadeChange = true;
return OptimizeBlock(MBB);
}
}
if (!CurFallsThru) {
// Check all successors to see if we can move this block before it.
for (MachineBasicBlock::succ_iterator SI = MBB->succ_begin(),
E = MBB->succ_end(); SI != E; ++SI) {

71
test/CodeGen/Generic/2007-02-16-BranchFold.ll Normal file
View File

@ -0,0 +1,71 @@
; RUN: llvm-as < %s | llc &&
; RUN: llvm-as < %s | llc | grep jmp | wc -l | grep 0
; ModuleID = 'bugpoint.test.bc'
target datalayout = "e-p:32:32"
target triple = "i686-apple-darwin8"
%struct.FILE = type { i8*, i32, i32, i16, i16, %struct.__sbuf, i32, i8*, i32 (i8*)*, i32 (i8*, i8*, i32)*, i64 (i8*, i64, i32)*, i32 (i8*, i8*, i32)*, %struct.__sbuf, %struct.__sFILEX*, i32, [3 x i8], [1 x i8], %struct.__sbuf, i32, i64 }
%struct.Index_Map = type { i32, %struct.item_set** }
%struct.Item = type { [4 x i16], %struct.rule* }
%struct.__sFILEX = type opaque
%struct.__sbuf = type { i8*, i32 }
%struct.dimension = type { i16*, %struct.Index_Map, %struct.mapping*, i32, %struct.plankMap* }
%struct.item_set = type { i32, i32, %struct.operator*, [2 x %struct.item_set*], %struct.item_set*, i16*, %struct.Item*, %struct.Item* }
%struct.list = type { i8*, %struct.list* }
%struct.mapping = type { %struct.list**, i32, i32, i32, %struct.item_set** }
%struct.nonterminal = type { i8*, i32, i32, i32, %struct.plankMap*, %struct.rule* }
%struct.operator = type { i8*, i8, i32, i32, i32, i32, %struct.table* }
%struct.pattern = type { %struct.nonterminal*, %struct.operator*, [2 x %struct.nonterminal*] }
%struct.plank = type { i8*, %struct.list*, i32 }
%struct.plankMap = type { %struct.list*, i32, %struct.stateMap* }
%struct.rule = type { [4 x i16], i32, i32, i32, %struct.nonterminal*, %struct.pattern*, i8 }
%struct.stateMap = type { i8*, %struct.plank*, i32, i16* }
%struct.table = type { %struct.operator*, %struct.list*, i16*, [2 x %struct.dimension*], %struct.item_set** }
@outfile = external global %struct.FILE* ; <%struct.FILE**> [#uses=1]
@str1 = external global [11 x i8] ; <[11 x i8]*> [#uses=1]
implementation ; Functions:
declare i32 @fprintf(%struct.FILE*, i8*, ...)
define i16 @main_bb_2E_i9_2E_i_2E_i932_2E_ce(%struct.list* %l_addr.01.0.i2.i.i929, %struct.operator** %tmp66.i62.i.out) {
newFuncRoot:
br label %bb.i9.i.i932.ce
bb36.i.i.exitStub: ; preds = %bb.i9.i.i932.ce
store %struct.operator* %tmp66.i62.i, %struct.operator** %tmp66.i62.i.out
ret i16 0
bb.i14.i.exitStub: ; preds = %bb.i9.i.i932.ce
store %struct.operator* %tmp66.i62.i, %struct.operator** %tmp66.i62.i.out
ret i16 1
bb12.i.i935.exitStub: ; preds = %bb.i9.i.i932.ce
store %struct.operator* %tmp66.i62.i, %struct.operator** %tmp66.i62.i.out
ret i16 2
bb20.i.i937.exitStub: ; preds = %bb.i9.i.i932.ce
store %struct.operator* %tmp66.i62.i, %struct.operator** %tmp66.i62.i.out
ret i16 3
bb28.i.i938.exitStub: ; preds = %bb.i9.i.i932.ce
store %struct.operator* %tmp66.i62.i, %struct.operator** %tmp66.i62.i.out
ret i16 4
bb.i9.i.i932.ce: ; preds = %newFuncRoot
%tmp1.i3.i.i930 = getelementptr %struct.list* %l_addr.01.0.i2.i.i929, i32 0, i32 0 ; <i8**> [#uses=1]
%tmp2.i4.i.i931 = load i8** %tmp1.i3.i.i930 ; <i8*> [#uses=1]
%tmp66.i62.i = bitcast i8* %tmp2.i4.i.i931 to %struct.operator* ; <%struct.operator*> [#uses=7]
%tmp1.i6.i = getelementptr %struct.operator* %tmp66.i62.i, i32 0, i32 2 ; <i32*> [#uses=1]
%tmp2.i7.i = load i32* %tmp1.i6.i ; <i32> [#uses=1]
%tmp3.i8.i = load %struct.FILE** @outfile ; <%struct.FILE*> [#uses=1]
%tmp5.i9.i = call i32 (%struct.FILE*, i8*, ...)* @fprintf( %struct.FILE* %tmp3.i8.i, i8* getelementptr ([11 x i8]* @str1, i32 0, i32 0), i32 %tmp2.i7.i ) ; <i32> [#uses=0]
%tmp7.i10.i = getelementptr %struct.operator* %tmp66.i62.i, i32 0, i32 5 ; <i32*> [#uses=1]
%tmp8.i11.i = load i32* %tmp7.i10.i ; <i32> [#uses=1]
switch i32 %tmp8.i11.i, label %bb36.i.i.exitStub [
i32 -1, label %bb.i14.i.exitStub
i32 0, label %bb12.i.i935.exitStub
i32 1, label %bb20.i.i937.exitStub
i32 2, label %bb28.i.i938.exitStub
]
}

3
test/CodeGen/PowerPC/branch-opt.ll
View File

@ -1,5 +1,6 @@
; RUN: llvm-upgrade < %s | llvm-as | llc -march=ppc32 &&
; RUN: llvm-upgrade < %s | llvm-as | llc -march=ppc32 | grep 'b LBB.*cond_next48.loopexit' | wc -l | grep 1
; RUN: llvm-upgrade < %s | llvm-as | llc -march=ppc32 | grep 'b LBB.*' | wc -l | grep 5
;;; FIXME, 4 unconditional branches is minimal
target endian = big
target pointersize = 32

2
test/CodeGen/X86/2006-10-19-SwitchUnnecessaryBranching.ll
View File

@ -1,4 +1,4 @@
; RUN: llvm-upgrade < %s | llvm-as | llc -march=x86 | %prcontext je 1 | grep "BB1_4:"
; RUN: llvm-upgrade < %s | llvm-as | llc -march=x86 | %prcontext je 1 | grep "BB1_1:"
%str = internal constant [14 x sbyte] c"Hello world!\0A\00" ; <[14 x sbyte]*> [#uses=1]
%str = internal constant [13 x sbyte] c"Blah world!\0A\00" ; <[13 x sbyte]*> [#uses=1]