[llvm] [TableGen] Halt !if resolution for unresolved condition (PR #107823)

[Akshat Oke via llvm-commits]

https://github.com/Akshat-Oke created https://github.com/llvm/llvm-project/pull/107823

`MHS` should not be resolved if we don't yet know which branch is to be taken.

>From 6526f13d5e44dac2bf1348c7b3961044b6d1901b Mon Sep 17 00:00:00 2001
From: Akshat Oke <Akshat.Oke at amd.com>
Date: Mon, 9 Sep 2024 08:28:25 +0000
Subject: [PATCH] [TableGen] Halt !if resolution for unresolved condition

---
 llvm/lib/TableGen/Record.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/llvm/lib/TableGen/Record.cpp b/llvm/lib/TableGen/Record.cpp
index 85516b7b9f20aa..cd855b6d43dd82 100644
--- a/llvm/lib/TableGen/Record.cpp
+++ b/llvm/lib/TableGen/Record.cpp
@@ -1876,6 +1876,11 @@ Init *TernOpInit::resolveReferences(Resolver &R) const {
       return RHS->resolveReferences(R);
     }
   }
+  if (getOpcode() == IF && !lhs->isConcrete()) {
+    // do not proceed since we don't know the condition's value
+    return (TernOpInit::get(getOpcode(), lhs, MHS, RHS, getType()))
+        ->Fold(R.getCurrentRecord());
+  }
 
   Init *mhs = MHS->resolveReferences(R);
   Init *rhs;