Fix cmp emission on msp430: we definitely should turn stuff like

"icmp lhs, rhs" into "cmp rhs, lhs". This should fix PR5979.

llvm-svn: 93496

Author: asl

llvm/lib/Target/MSP430/MSP430ISelLowering.cpp

@@ -660,16 +660,16 @@ static SDValue EmitCMP(SDValue &LHS, SDValue &RHS, SDValue &TargetCC,
   default: llvm_unreachable("Invalid integer condition!");
   case ISD::SETEQ:
     TCC = MSP430CC::COND_E;     // aka COND_Z
-    // Minor optimization: if RHS is a constant, swap operands, then the
+    // Minor optimization: if LHS is a constant, swap operands, then the
     // constant can be folded into comparison.
-    if (RHS.getOpcode() == ISD::Constant)
+    if (LHS.getOpcode() == ISD::Constant)
       std::swap(LHS, RHS);
     break;
   case ISD::SETNE:
     TCC = MSP430CC::COND_NE;    // aka COND_NZ
-    // Minor optimization: if RHS is a constant, swap operands, then the
+    // Minor optimization: if LHS is a constant, swap operands, then the
     // constant can be folded into comparison.
-    if (RHS.getOpcode() == ISD::Constant)
+    if (LHS.getOpcode() == ISD::Constant)
       std::swap(LHS, RHS);
     break;
   case ISD::SETULE:
@@ -1014,8 +1014,8 @@ MSP430TargetLowering::EmitShiftInstr(MachineInstr *MI,
   // BB:
   // cmp 0, N
   // je RemBB
-  BuildMI(BB, dl, TII.get(MSP430::CMP8ir))
-    .addImm(0).addReg(ShiftAmtSrcReg);
+  BuildMI(BB, dl, TII.get(MSP430::CMP8ri))
+    .addReg(ShiftAmtSrcReg).addImm(0);
   BuildMI(BB, dl, TII.get(MSP430::JCC))
     .addMBB(RemBB)
     .addImm(MSP430CC::COND_E);

llvm/lib/Target/MSP430/MSP430InstrInfo.td

@@ -819,38 +819,40 @@ def SWPB16r : Pseudo<(outs GR16:$dst), (ins GR16:$src),
 // Integer comparisons
 let Defs = [SRW] in {
 def CMP8rr  : Pseudo<(outs), (ins GR8:$src1, GR8:$src2),
-                     "cmp.b\t{$src1, $src2}",
+                     "cmp.b\t{$src2, $src1}",
                      [(MSP430cmp GR8:$src1, GR8:$src2), (implicit SRW)]>;
 def CMP16rr : Pseudo<(outs), (ins GR16:$src1, GR16:$src2),
-                     "cmp.w\t{$src1, $src2}",
+                     "cmp.w\t{$src2, $src1}",
                      [(MSP430cmp GR16:$src1, GR16:$src2), (implicit SRW)]>;
 
-def CMP8ir  : Pseudo<(outs), (ins i8imm:$src1, GR8:$src2),
-                   "cmp.b\t{$src1, $src2}",
-                   [(MSP430cmp imm:$src1, GR8:$src2), (implicit SRW)]>;
-def CMP16ir : Pseudo<(outs), (ins i16imm:$src1, GR16:$src2),
-                     "cmp.w\t{$src1, $src2}",
-                     [(MSP430cmp imm:$src1, GR16:$src2), (implicit SRW)]>;
-
-def CMP8im  : Pseudo<(outs), (ins i8imm:$src1, memsrc:$src2),
-                     "cmp.b\t{$src1, $src2}",
-                      [(MSP430cmp (i8 imm:$src1), (load addr:$src2)), (implicit SRW)]>;
-def CMP16im : Pseudo<(outs), (ins i16imm:$src1, memsrc:$src2),
-                     "cmp.w\t{$src1, $src2}",
-                      [(MSP430cmp (i16 imm:$src1), (load addr:$src2)), (implicit SRW)]>;
+def CMP8ri  : Pseudo<(outs), (ins GR8:$src1, i8imm:$src2),
+                   "cmp.b\t{$src2, $src1}",
+                   [(MSP430cmp GR8:$src1, imm:$src2), (implicit SRW)]>;
+def CMP16ri : Pseudo<(outs), (ins GR16:$src1, i16imm:$src2),
+                     "cmp.w\t{$src2, $src1}",
+                     [(MSP430cmp GR16:$src1, imm:$src2), (implicit SRW)]>;
+
+def CMP8mi  : Pseudo<(outs), (ins memsrc:$src1, i8imm:$src2),
+                     "cmp.b\t{$src2, $src1}",
+                      [(MSP430cmp (load addr:$src1),
+                                  (i8 imm:$src2)), (implicit SRW)]>;
+def CMP16mi : Pseudo<(outs), (ins memsrc:$src1, i16imm:$src2),
+                     "cmp.w\t{$src2, $src1}",
+                      [(MSP430cmp (load addr:$src1),
+                                  (i16 imm:$src2)), (implicit SRW)]>;
 
 def CMP8rm  : Pseudo<(outs), (ins GR8:$src1, memsrc:$src2),
-                     "cmp.b\t{$src1, $src2}",
+                     "cmp.b\t{$src2, $src1}",
                      [(MSP430cmp GR8:$src1, (load addr:$src2)), (implicit SRW)]>;
 def CMP16rm : Pseudo<(outs), (ins GR16:$src1, memsrc:$src2),
-                     "cmp.w\t{$src1, $src2}",
+                     "cmp.w\t{$src2, $src1}",
                      [(MSP430cmp GR16:$src1, (load addr:$src2)), (implicit SRW)]>;
 
 def CMP8mr  : Pseudo<(outs), (ins memsrc:$src1, GR8:$src2),
-                "cmp.b\t{$src1, $src2}",
+                "cmp.b\t{$src2, $src1}",
                 [(MSP430cmp (load addr:$src1), GR8:$src2), (implicit SRW)]>;
 def CMP16mr : Pseudo<(outs), (ins memsrc:$src1, GR16:$src2),
-                "cmp.w\t{$src1, $src2}",
+                "cmp.w\t{$src2, $src1}",
                 [(MSP430cmp (load addr:$src1), GR16:$src2), (implicit SRW)]>;