[FIRRTL][LowerType] Handle unrealized_conversion_cast of other dialec…

…ts (#6422) LowerTypes was crashing when lowering `unrealized_conversion_cast` from other dialects. This PR fixes the crash and ignores the cast op from other dialects instead of lowering them.
llvm · Nov 17, 2023 · 8da7ce4 · 8da7ce4
1 parent bca67e6
commit 8da7ce4
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Showing 2 changed files with 14 additions and 2 deletions.
diff --git a/lib/Dialect/FIRRTL/Transforms/LowerTypes.cpp b/lib/Dialect/FIRRTL/Transforms/LowerTypes.cpp
@@ -1334,6 +1334,10 @@ bool TypeLoweringVisitor::visitExpr(mlir::UnrealizedConversionCastOp op) {
     return builder->create<mlir::UnrealizedConversionCastOp>(field.type, input)
         .getResult(0);
   };
+  // If the input to the cast is not a FIRRTL type, getSubWhatever cannot handle
+  // it, donot lower the op.
+  if (!type_isa<FIRRTLType>(op->getOperand(0).getType()))
+    return false;
   return lowerProducer(op, clone);
 }
 

diff --git a/test/Dialect/FIRRTL/lower-types.mlir b/test/Dialect/FIRRTL/lower-types.mlir
@@ -1,5 +1,5 @@
-// RUN: circt-opt -pass-pipeline='builtin.module(firrtl.circuit(firrtl-lower-types))' %s | FileCheck --check-prefixes=CHECK,COMMON %s
-// RUN: circt-opt -pass-pipeline='builtin.module(firrtl.circuit(firrtl-lower-types{preserve-aggregate=all}))' %s | FileCheck --check-prefixes=AGGREGATE,COMMON %s
+// RUN: circt-opt -pass-pipeline='builtin.module(firrtl.circuit(firrtl-lower-types))' --allow-unregistered-dialect %s | FileCheck --check-prefixes=CHECK,COMMON %s
+// RUN: circt-opt -pass-pipeline='builtin.module(firrtl.circuit(firrtl-lower-types{preserve-aggregate=all}))' --allow-unregistered-dialect %s | FileCheck --check-prefixes=AGGREGATE,COMMON %s
 
 
 firrtl.circuit "TopLevel" {
@@ -1363,4 +1363,12 @@ firrtl.circuit "WireProbe" {
     firrtl.ref.define %y, %sp_y : !firrtl.probe<uint<5>>
     firrtl.ref.define %z, %sp_z : !firrtl.probe<uint<5>>
   }
+  firrtl.module @UnrealizedConversion( ){
+    // CHECK: %[[a:.+]] = "d.w"() : () -> !hw.struct<data: i64, tag: i1>
+    // CHECK: = builtin.unrealized_conversion_cast %[[a]] : !hw.struct<data: i64, tag: i1> to !firrtl.bundle<data: uint<64>, tag: uint<1>>
+    %a = "d.w"() : () -> (!hw.struct<data: i64, tag: i1>)
+    %b = builtin.unrealized_conversion_cast %a : !hw.struct<data: i64, tag: i1> to !firrtl.bundle<data: uint<64>, tag: uint<1>>
+    %w = firrtl.wire : !firrtl.bundle<data: uint<64>, tag: uint<1>>
+    firrtl.strictconnect %w, %b : !firrtl.bundle<data: uint<64>, tag: uint<1>>
+  }
 }