[SILOpt] Turn off PruneVTables.

varungandhi-apple · varungandhi-apple · commit fe4eff910187 · 2021-01-27T14:50:37.000-08:00
Fixes rdar://73638176.
diff --git a/lib/SILOptimizer/PassManager/PassPipeline.cpp b/lib/SILOptimizer/PassManager/PassPipeline.cpp
@@ -690,7 +690,8 @@ static void addLastChanceOptPassPipeline(SILPassPipelinePlan &P) {
   // Only has an effect if opt-remark is enabled.
   P.addOptRemarkGenerator();
 
-  P.addPruneVTables();
+  // FIXME: rdar://72935649 (Miscompile on combining PruneVTables with WMO)
+  // P.addPruneVTables();
 }
 
 static void addSILDebugInfoGeneratorPipeline(SILPassPipelinePlan &P) {

Original file line number	Diff line number	Diff line change
`@@ -690,7 +690,8 @@ static void addLastChanceOptPassPipeline(SILPassPipelinePlan &P) {`
`690`	`690`	`// Only has an effect if opt-remark is enabled.`
`691`	`691`	`P.addOptRemarkGenerator();`
`692`	`692`
`693`		`- P.addPruneVTables();`
	`693`	`+ // FIXME: rdar://72935649 (Miscompile on combining PruneVTables with WMO)`
	`694`	`+ // P.addPruneVTables();`
`694`	`695`	`}`
`695`	`696`
`696`	`697`	`static void addSILDebugInfoGeneratorPipeline(SILPassPipelinePlan &P) {`