[llvm] [MIR] Allow overriding isSSA, noPhis, noVRegs in MIR input (PR #108546)

[Dominik Montada via llvm-commits]

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@@ -0,0 +1,42 @@
+# RUN: llc -run-pass none -o - %s | FileCheck %s
+# Test that we can disable certain properties that are normally computed
+
+---
+# CHECK-LABEL: name: TestNoPhis
+# CHECK: noPhis: true
+# CHECK: ...
+name:            TestNoPhis
+...
+---
+# CHECK-LABEL: name: TestNoPhisOverride
+# CHECK: noPhis: false
+# CHECK: ...
+name:            TestNoPhisOverride
+noPhis: false
+...
+---
+# CHECK-LABEL: name: TestIsSSA
+# CHECK: isSSA: true
+# CHECK: ...
+name:            TestIsSSA
+...
+---
+# CHECK-LABEL: name: TestIsSSAOverride
+# CHECK: isSSA: false
+# CHECK: ...
+name:            TestIsSSAOverride
+isSSA: false
+...
+---
+# CHECK-LABEL: name: TestNoVRegs
+# CHECK: noVRegs: true
+# CHECK: ...
+name:            TestNoVRegs
+...
+---
+# CHECK-LABEL: name: TestNoVRegsOverride
+# CHECK: noVRegs: false
+# CHECK: ...
+name:            TestNoVRegsOverride
+noVRegs: false
+...
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gargaroff wrote:

The implementation here is more of a soft-override, i.e. if you set the property to `true` (the default) but the parser computes `false`, then the computed value is taken. It only really allows you to force the property to a less-strict value (`false` in this case).

I added some more tests with explicit true values, including conflicting values.

https://github.com/llvm/llvm-project/pull/108546