[mips] Make "b" (unconditional branch) a pseudo. "b" is an assembly idiom, which is
equivalent to "beq $zero, $zero, offset".
llvm-svn: 190220
diff --git a/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp b/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
index 755a948..231d485 100644
--- a/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
+++ b/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
@@ -230,8 +230,11 @@
bool MipsInstPrinter::printAlias(const MCInst &MI, raw_ostream &OS) {
switch (MI.getOpcode()) {
case Mips::BEQ:
+ // beq $zero, $zero, $L2 => b $L2
// beq $r0, $zero, $L2 => beqz $r0, $L2
- return isReg<Mips::ZERO>(MI, 1) && printAlias("beqz", MI, 0, 2, OS);
+ return isReg<Mips::ZERO>(MI, 0) && isReg<Mips::ZERO>(MI, 1) &&
+ printAlias("b", MI, 2, OS) ||
+ isReg<Mips::ZERO>(MI, 1) && printAlias("beqz", MI, 0, 2, OS);
case Mips::BEQ64:
// beq $r0, $zero, $L2 => beqz $r0, $L2
return isReg<Mips::ZERO_64>(MI, 1) && printAlias("beqz", MI, 0, 2, OS);
diff --git a/llvm/lib/Target/Mips/MipsCodeEmitter.cpp b/llvm/lib/Target/Mips/MipsCodeEmitter.cpp
index eed1155..0f1917a 100644
--- a/llvm/lib/Target/Mips/MipsCodeEmitter.cpp
+++ b/llvm/lib/Target/Mips/MipsCodeEmitter.cpp
@@ -323,6 +323,10 @@
BuildMI(MBB, &*MI, MI->getDebugLoc(), II->get(Mips::SLL), Mips::ZERO)
.addReg(Mips::ZERO).addImm(0);
break;
+ case Mips::B:
+ BuildMI(MBB, &*MI, MI->getDebugLoc(), II->get(Mips::BEQ)).addReg(Mips::ZERO)
+ .addReg(Mips::ZERO).addOperand(MI->getOperand(0));
+ break;
case Mips::JALRPseudo:
BuildMI(MBB, &*MI, MI->getDebugLoc(), II->get(Mips::JALR), Mips::RA)
.addReg(MI->getOperand(0).getReg());
diff --git a/llvm/lib/Target/Mips/MipsInstrFormats.td b/llvm/lib/Target/Mips/MipsInstrFormats.td
index f87d70e..c536264 100644
--- a/llvm/lib/Target/Mips/MipsInstrFormats.td
+++ b/llvm/lib/Target/Mips/MipsInstrFormats.td
@@ -297,17 +297,6 @@
let Inst{15-0} = offset;
}
-class B_FM {
- bits<16> offset;
-
- bits<32> Inst;
-
- let Inst{31-26} = 4;
- let Inst{25-21} = 0;
- let Inst{20-16} = 0;
- let Inst{15-0} = offset;
-}
-
class SLTI_FM<bits<6> op> : StdArch {
bits<5> rt;
bits<5> rs;
diff --git a/llvm/lib/Target/Mips/MipsInstrInfo.td b/llvm/lib/Target/Mips/MipsInstrInfo.td
index 8b985a8..83c7885 100644
--- a/llvm/lib/Target/Mips/MipsInstrInfo.td
+++ b/llvm/lib/Target/Mips/MipsInstrInfo.td
@@ -542,9 +542,9 @@
}
// Unconditional branch
-class UncondBranch<string opstr> :
- InstSE<(outs), (ins brtarget:$offset), !strconcat(opstr, "\t$offset"),
- [(br bb:$offset)], IIBranch, FrmI> {
+class UncondBranch<Instruction BEQInst> :
+ PseudoSE<(outs), (ins brtarget:$offset), [(br bb:$offset)], IIBranch>,
+ PseudoInstExpansion<(BEQInst ZERO, ZERO, brtarget:$offset)> {
let isBranch = 1;
let isTerminator = 1;
let isBarrier = 1;
@@ -966,13 +966,13 @@
def J : JumpFJ<jmptarget, "j", br, bb>, FJ<2>,
Requires<[RelocStatic, HasStdEnc]>, IsBranch;
def JR : IndirectBranch<GPR32Opnd>, MTLO_FM<8>;
-def B : UncondBranch<"b">, B_FM;
def BEQ : CBranch<"beq", seteq, GPR32Opnd>, BEQ_FM<4>;
def BNE : CBranch<"bne", setne, GPR32Opnd>, BEQ_FM<5>;
def BGEZ : CBranchZero<"bgez", setge, GPR32Opnd>, BGEZ_FM<1, 1>;
def BGTZ : CBranchZero<"bgtz", setgt, GPR32Opnd>, BGEZ_FM<7, 0>;
def BLEZ : CBranchZero<"blez", setle, GPR32Opnd>, BGEZ_FM<6, 0>;
def BLTZ : CBranchZero<"bltz", setlt, GPR32Opnd>, BGEZ_FM<1, 0>;
+def B : UncondBranch<BEQ>;
def JAL : JumpLink<"jal">, FJ<3>;
def JALR : JumpLinkReg<"jalr", GPR32Opnd>, JALR_FM;
@@ -1100,6 +1100,7 @@
def : InstAlias<"mtc0 $rt, $rd", (MTC0 GPR32Opnd:$rt, GPR32Opnd:$rd, 0), 0>;
def : InstAlias<"mfc2 $rt, $rd", (MFC2 GPR32Opnd:$rt, GPR32Opnd:$rd, 0), 0>;
def : InstAlias<"mtc2 $rt, $rd", (MTC2 GPR32Opnd:$rt, GPR32Opnd:$rd, 0), 0>;
+def : InstAlias<"b $offset", (BEQ ZERO, ZERO, brtarget:$offset), 0>;
def : InstAlias<"bnez $rs,$offset",
(BNE GPR32Opnd:$rs, ZERO, brtarget:$offset), 0>;
def : InstAlias<"beqz $rs,$offset",