[llvm] [Sparc] Replace CMP instructions with InstAlias (NFCI) (PR #66859)

[Sergei Barannikov via llvm-commits]

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@@ -829,23 +829,14 @@ defm SUB    : F3_12  <"sub"  , 0b000100, sub, IntRegs, i32, simm13Op>;
 let Uses = [ICC], Defs = [ICC] in
   defm SUBE   : F3_12  <"subxcc" , 0b011100, sube, IntRegs, i32, simm13Op>;
 
-let Defs = [ICC] in
+let Defs = [ICC], hasPostISelHook = true in
   defm SUBCC  : F3_12  <"subcc", 0b010100, subc, IntRegs, i32, simm13Op>;
 
 let Uses = [ICC] in
   defm SUBC   : F3_12np <"subx", 0b001100>;
 
-// cmp (from Section A.3) is a specialized alias for subcc
-let Defs = [ICC], rd = 0 in {
-  def CMPrr   : F3_1<2, 0b010100,
-                     (outs), (ins IntRegs:$rs1, IntRegs:$rs2),
-                     "cmp $rs1, $rs2",
-                     [(SPcmpicc i32:$rs1, i32:$rs2)]>;
-  def CMPri   : F3_2<2, 0b010100,
-                     (outs), (ins IntRegs:$rs1, simm13Op:$simm13),
-                     "cmp $rs1, $simm13",
-                     [(SPcmpicc i32:$rs1, (i32 simm13:$simm13))]>;
-}
+def : Pat<(SPcmpicc i32:$lhs, i32:$rhs), (SUBCCri $lhs, $rhs)>;
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s-barannikov wrote:

It should. Sharp eye!
I will try to investigate why tests didn't catch this.

https://github.com/llvm/llvm-project/pull/66859