Compile CodeGen/PowerPC/fp-branch.ll to:

_intcoord_cond_next55:
LBB1_3: ;cond_next55
        lis r2, ha16(LCPI1_0)
        lfs f0, lo16(LCPI1_0)(r2)
        fcmpu cr0, f1, f0
        blt cr0, LBB1_2 ;cond_next62.exitStub
LBB1_1: ;bb72.exitStub
        li r3, 1
        blr
LBB1_2: ;cond_next62.exitStub
        li r3, 0
        blr

instead of:

_intcoord_cond_next55:
LBB1_3: ;cond_next55
        lis r2, ha16(LCPI1_0)
        lfs f0, lo16(LCPI1_0)(r2)
        fcmpu cr0, f1, f0
        bge cr0, LBB1_1 ;bb72.exitStub
LBB1_4: ;cond_next55
        lis r2, ha16(LCPI1_0)
        lfs f0, lo16(LCPI1_0)(r2)
        fcmpu cr0, f1, f0
        bnu cr0, LBB1_2 ;cond_next62.exitStub
LBB1_1: ;bb72.exitStub
        li r3, 1
        blr
LBB1_2: ;cond_next62.exitStub
        li r3, 0
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31330 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-10-31 23:06:00 +00:00
parent 04ffebc798
commit 0ccb500fa7

View File

@ -975,6 +975,15 @@ static bool
ShouldEmitAsBranches(const std::vector<SelectionDAGISel::CaseBlock> &Cases) {
if (Cases.size() != 2) return true;
// If this is two comparisons of the same values or'd or and'd together, they
// will get folded into a single comparison, so don't emit two blocks.
if ((Cases[0].CmpLHS == Cases[1].CmpLHS &&
Cases[0].CmpRHS == Cases[1].CmpRHS) ||
(Cases[0].CmpRHS == Cases[1].CmpLHS &&
Cases[0].CmpLHS == Cases[1].CmpRHS)) {
return false;
}
return true;
}
@ -1025,14 +1034,13 @@ void SelectionDAGLowering::visitBr(BranchInst &I) {
(BOp->getOpcode() == Instruction::And ||
BOp->getOpcode() == Instruction::Or)) {
FindMergedConditions(BOp, Succ0MBB, Succ1MBB, CurMBB, BOp->getOpcode());
// If the compares in later blocks need to use values not currently
// exported from this block, export them now. This block should always
// be the first entry.
assert(SwitchCases[0].ThisBB == CurMBB && "Unexpected lowering!");
// Allow some cases to be rejected.
if (ShouldEmitAsBranches(SwitchCases)) {
// If the compares in later blocks need to use values not currently
// exported from this block, export them now. This block should always
// be the first entry.
assert(SwitchCases[0].ThisBB == CurMBB && "Unexpected lowering!");
for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i) {
ExportFromCurrentBlock(SwitchCases[i].CmpLHS);
ExportFromCurrentBlock(SwitchCases[i].CmpRHS);
@ -1044,6 +1052,11 @@ void SelectionDAGLowering::visitBr(BranchInst &I) {
return;
}
// Okay, we decided not to do this, remove any inserted MBB's and clear
// SwitchCases.
for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i)
CurMBB->getParent()->getBasicBlockList().erase(SwitchCases[i].ThisBB);
SwitchCases.clear();
}
}