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Revert r97766. It's deleting a tag. 

llvm-svn: 97768
This commit is contained in:
Bill Wendling 2010-03-05 00:33:59 +00:00
parent 90d4717767
commit 543ce1f64a
2 changed files with 13 additions and 74 deletions
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65
llvm/lib/Target/X86/X86InstrInfo.cpp
View File

@ -1786,7 +1786,6 @@ X86InstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
const SmallVectorImpl<MachineOperand> &Cond) const {
// FIXME this should probably have a DebugLoc operand
DebugLoc dl = DebugLoc::getUnknownLoc();
// Shouldn't be a fall through.
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 1 || Cond.size() == 0) &&
@ -1800,72 +1799,34 @@ X86InstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
}
// Conditional branch.
const MachineBasicBlock *NextBB = next(&MBB);
unsigned Count = 0;
X86::CondCode CC = (X86::CondCode)Cond[0].getImm();
// In a two-way conditional branch, if the fall-through block is the
// "false" branch of the conditional jumps, we can cut out the
// unconditional jump by rearranging the conditional jumps. This saves a
// few bytes and improves performance. I.e., for COND_NE_OR_P:
//
// JNE L1
// JP L1
// JMP L2
// L1:
// ...
// L2:
// ...
//
// to:
//
// JP L1
// JE L2
// L1:
// ...
// L2:
// ...
//
// Similarly for COND_NP_OR_E.
switch (CC) {
default:
BuildMI(&MBB, dl, get(GetCondBranchFromCond(CC))).addMBB(TBB);
++Count;
break;
case X86::COND_NP_OR_E:
// Synthesize NP_OR_E with two branches.
if (FBB && FBB == NextBB) {
BuildMI(&MBB, dl, get(X86::JNP_4)).addMBB(TBB);
BuildMI(&MBB, dl, get(X86::JNE_4)).addMBB(FBB);
FBB = 0;
} else {
BuildMI(&MBB, dl, get(X86::JNP_4)).addMBB(TBB);
BuildMI(&MBB, dl, get(X86::JE_4)).addMBB(TBB);
}
Count += 2;
BuildMI(&MBB, dl, get(X86::JNP_4)).addMBB(TBB);
++Count;
BuildMI(&MBB, dl, get(X86::JE_4)).addMBB(TBB);
++Count;
break;
case X86::COND_NE_OR_P:
// Synthesize NE_OR_P with two branches.
if (FBB && FBB == NextBB) {
BuildMI(&MBB, dl, get(X86::JP_4)).addMBB(TBB);
BuildMI(&MBB, dl, get(X86::JE_4)).addMBB(FBB);
FBB = 0;
} else {
BuildMI(&MBB, dl, get(X86::JNE_4)).addMBB(TBB);
BuildMI(&MBB, dl, get(X86::JP_4)).addMBB(TBB);
}
Count += 2;
BuildMI(&MBB, dl, get(X86::JNE_4)).addMBB(TBB);
++Count;
BuildMI(&MBB, dl, get(X86::JP_4)).addMBB(TBB);
++Count;
break;
default: {
unsigned Opc = GetCondBranchFromCond(CC);
BuildMI(&MBB, dl, get(Opc)).addMBB(TBB);
++Count;
}
}
if (FBB) {
// Two-way Conditional branch. Insert the second branch.
BuildMI(&MBB, dl, get(X86::JMP_4)).addMBB(FBB);
++Count;
}
return Count;
}

22
llvm/test/CodeGen/X86/jump-opt.ll
View File

@ -1,22 +0,0 @@
; RUN: llc < %s -mtriple=i386-apple-darwin10 | FileCheck %s
; <rdar://problem/7598384>
define float @test1(float %x, float %y) nounwind readnone optsize ssp {
; CHECK: jp
; CHECK-NEXT: je
entry:
%0 = fpext float %x to double
%1 = fpext float %y to double
%2 = fmul double %0, %1
%3 = fcmp oeq double %2, 0.000000e+00
br i1 %3, label %bb2, label %bb1
bb1:
%4 = fadd double %2, -1.000000e+00
br label %bb2
bb2:
%.0.in = phi double [ %4, %bb1 ], [ %2, %entry ]
%.0 = fptrunc double %.0.in to float
ret float %.0
}