[llvm] [SPIR-V] Lower G_SMULFIX and G_UMULFIX (PR #206507)

[Juan Manuel Martinez Caamaño via llvm-commits]

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@@ -458,6 +458,10 @@ SPIRVLegalizerInfo::SPIRVLegalizerInfo(const SPIRVSubtarget &ST) {
 
   getActionDefinitionsBuilder({G_SADDO, G_SSUBO}).lower();
 
+  getActionDefinitionsBuilder({G_SMULFIX, G_UMULFIX})
+      .unsupportedFor({s64})
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jmmartinez wrote:

Can we add a comment and a test explaining this?

https://github.com/llvm/llvm-project/pull/206507