diff options
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.cpp | 65 | ||||
| -rw-r--r-- | test/CodeGen/X86/jump-opt.ll | 22 |
2 files changed, 13 insertions, 74 deletions
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp index 0d3b54fe8e..39bda04b4d 100644 --- a/lib/Target/X86/X86InstrInfo.cpp +++ b/lib/Target/X86/X86InstrInfo.cpp @@ -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; } diff --git a/test/CodeGen/X86/jump-opt.ll b/test/CodeGen/X86/jump-opt.ll deleted file mode 100644 index dc32f6665f..0000000000 --- a/test/CodeGen/X86/jump-opt.ll +++ /dev/null @@ -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 -} |