[AArch64][GISel] Expand coverage of FAdd and FSub.

This adds some more extensive test coverage for fadd/fsub through global isel,
switching the opcodes to use the more complete ActionDefinitions to handle more
cases.

Author: davemgreen

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

@@ -4831,6 +4831,7 @@ LegalizerHelper::moreElementsVector(MachineInstr &MI, unsigned TypeIdx,
   case TargetOpcode::G_SUB:
   case TargetOpcode::G_MUL:
   case TargetOpcode::G_FADD:
+  case TargetOpcode::G_FSUB:
   case TargetOpcode::G_FMUL:
   case TargetOpcode::G_UADDSAT:
   case TargetOpcode::G_USUBSAT:

llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp

@@ -235,7 +235,7 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST)
        .clampScalar(1, s32, s64)
       .widenScalarToNextPow2(0);
 
-  getActionDefinitionsBuilder({G_FADD, G_FSUB, G_FMUL, G_FDIV, G_FNEG})
+  getActionDefinitionsBuilder({G_FMUL, G_FDIV, G_FNEG})
       .legalFor({MinFPScalar, s32, s64, v2s64, v4s32, v2s32})
       .clampScalar(0, MinFPScalar, s64)
       .clampNumElements(0, v2s32, v4s32)
@@ -948,10 +948,10 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST)
   // TODO: Vector types.
   getActionDefinitionsBuilder({G_SADDSAT, G_SSUBSAT}).lowerIf(isScalar(0));
 
-  getActionDefinitionsBuilder({G_FABS, G_FSQRT, G_FMAXNUM, G_FMINNUM, G_FMAXIMUM,
-                               G_FMINIMUM, G_FCEIL, G_FFLOOR, G_FRINT,
-                               G_FNEARBYINT, G_INTRINSIC_TRUNC,
-                               G_INTRINSIC_ROUND, G_INTRINSIC_ROUNDEVEN})
+  getActionDefinitionsBuilder(
+      {G_FADD, G_FSUB, G_FABS, G_FSQRT, G_FMAXNUM, G_FMINNUM, G_FMAXIMUM,
+       G_FMINIMUM, G_FCEIL, G_FFLOOR, G_FRINT, G_FNEARBYINT, G_INTRINSIC_TRUNC,
+       G_INTRINSIC_ROUND, G_INTRINSIC_ROUNDEVEN})
       .legalFor({MinFPScalar, s32, s64, v2s32, v4s32, v2s64})
       .legalIf([=](const LegalityQuery &Query) {
         const auto &Ty = Query.Types[0];

llvm/test/CodeGen/AArch64/GlobalISel/legalizer-info-validation.mir

@@ -431,14 +431,13 @@
 # DEBUG-NEXT: .. type index coverage check SKIPPED: no rules defined
 # DEBUG-NEXT: .. imm index coverage check SKIPPED: no rules defined
 # DEBUG-NEXT: G_FADD (opcode {{[0-9]+}}): 1 type index, 0 imm indices
-# DEBUG-NEXT: .. the first uncovered type index: 1, OK
-# DEBUG-NEXT: .. the first uncovered imm index: 0, OK
+# DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
+# DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: G_FSUB (opcode {{[0-9]+}}): 1 type index, 0 imm indices
 # DEBUG-NEXT: .. opcode {{[0-9]+}} is aliased to {{[0-9]+}}
-# DEBUG-NEXT: .. the first uncovered type index: 1, OK
-# DEBUG-NEXT: .. the first uncovered imm index: 0, OK
+# DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
+# DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: G_FMUL (opcode {{[0-9]+}}): 1 type index, 0 imm indices
-# DEBUG-NEXT: .. opcode {{[0-9]+}} is aliased to {{[0-9]+}}
 # DEBUG-NEXT: .. the first uncovered type index: 1, OK
 # DEBUG-NEXT: .. the first uncovered imm index: 0, OK
 # DEBUG-NEXT: G_FMA (opcode {{[0-9]+}}): 1 type index, 0 imm indices
@@ -512,6 +511,7 @@
 # DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: G_FABS (opcode {{[0-9]+}}): 1 type index, 0 imm indices
+# DEBUG-NEXT: .. opcode {{[0-9]+}} is aliased to {{[0-9]+}}
 # DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: G_FCOPYSIGN (opcode {{[0-9]+}}): 2 type indices