Change setting logic, include full error message, use G_IMPLICIT_DEF

Author: gargaroff

llvm/lib/CodeGen/MIRParser/MIRParser.cpp

@@ -406,27 +406,12 @@ bool MIRParserImpl::computeFunctionProperties(
   auto ComputedPropertyHelper =
       [&Properties](std::optional<bool> ExplicitProp, bool ComputedProp,
                     MachineFunctionProperties::Property P) -> bool {
-    // Prefer whatever is set explicitly by the input MIR
-    if (ExplicitProp.has_value()) {
-      if (*ExplicitProp) {
-        // Check for conflicts with the computed value
-        if (!ComputedProp)
-          return true;
-
-        Properties.set(P);
-      } else
-        Properties.reset(P);
-
-      return false;
-    }
-
-    // No explicit value given, so use computed value
-    if (ComputedProp)
+    if (ExplicitProp.value_or(ComputedProp))
       Properties.set(P);
     else
       Properties.reset(P);
-
-    return false;
+    
+    return ExplicitProp && *ExplicitProp && !ComputedProp;
   };
 
   if (ComputedPropertyHelper(YamlMF.NoPHIs, !HasPHI,

llvm/test/CodeGen/MIR/Generic/machine-function-optionally-computed-properties-conflict.mir

@@ -4,35 +4,32 @@
 # properties
 
 ---
-# CHECK-LABEL: TestNoPhisOverrideConflict
-# CHECK-SAME: has explicit property NoPhi, but contains at least one PHI
+# CHECK: error: {{.*}}: TestNoPhisOverrideConflict has explicit property NoPhi, but contains at least one PHI
 name:            TestNoPhisOverrideConflict
 noPhis: true
 tracksRegLiveness: true
 body: |
   bb.0:
-    %0:_(s32) = IMPLICIT_DEF
+    %0:_(s32) = G_IMPLICIT_DEF
 
   bb.1:
     %1:_(s32) = PHI %0, %bb.0, %1, %bb.1
     G_BR %bb.1
 ...
 ---
-# CHECK-LABEL: TestIsSSAOverrideConflict
-# CHECK-SAME: has explicit property IsSSA, but is not valid SSA
+# CHECK: error: {{.*}}: TestIsSSAOverrideConflict has explicit property IsSSA, but is not valid SSA
 name:            TestIsSSAOverrideConflict
 isSSA: true
 body: |
   bb.0:
-    %0:_(s32) = IMPLICIT_DEF
-    %0:_(s32) = IMPLICIT_DEF
+    %0:_(s32) = G_IMPLICIT_DEF
+    %0:_(s32) = G_IMPLICIT_DEF
 ...
 ---
-# CHECK-LABEL: TestNoVRegsOverrideConflict
-# CHECK-SAME: has explicit property NoVRegs, but contains virtual registers
+# CHECK: error: {{.*}}: TestNoVRegsOverrideConflict has explicit property NoVRegs, but contains virtual registers
 name:            TestNoVRegsOverrideConflict
 noVRegs: true
 body: |
   bb.0:
-    %0:_(s32) = IMPLICIT_DEF
+    %0:_(s32) = G_IMPLICIT_DEF
 ...