[llvm] [AMDGPU] Create local KnownBits in case DenseMap gets invalidated (PR #111568)

[Matt Arsenault via llvm-commits]

================
@@ -1,120 +1,144 @@
-; REQUIRES: asserts
-; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1030 -o - %s 2>&1 | FileCheck %s
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1030 < %s | FileCheck %s
 
-; CHECK-NOT: Assertion `BitWidth == RHS.BitWidth && "Bit widths must be same for comparison"' failed
+; Previously, this would hit an assertion on incompatible comparison between
+; APInts due to BitWidth differences. This was due to assignment of DenseMap
+; value using another value within that same DenseMap which results in a
+; use-after-free if the assignment operator invokes a DenseMap growth.
 
-define void @RunTic() {
-  %call5.i1 = call i32 @G_CheckDemoStatus()
-  tail call void @D_AdvanceDemo()
-  call void @G_Ticker()
+; CHECK-LABEL: I_Quit:
+define void @I_Quit() {
+  %fptr = load ptr, ptr null, align 8
+  tail call void %fptr()
   ret void
 }
 
-define void @G_Ticker() {
-  call void @G_DoReborn()
-  tail call void @F_Ticker()
-  tail call void @AM_Stop()
-  tail call void @F_StartFinale()
-  tail call void @D_AdvanceDemo()
-  %call.i.i449 = call i32 @R_FlatNumForName()
-  %call9.i.i = call i32 @R_TextureNumForName()
-  %call.i306 = tail call ptr @P_TempSaveGameFile()
-  %call1.i307 = call ptr @P_SaveGameFile()
-  call void (...) @I_Error()
+; CHECK-LABEL: P_RemoveMobj:
+define void @P_RemoveMobj() {
   ret void
 }
 
-define void @G_DoReborn() {
-  call void @P_RemoveMobj()
-  call void @P_SpawnMobj()
-  call void @P_SpawnPlayer()
-  call void (...) @I_Error()
+; CHECK-LABEL: P_SpawnMobj:
+define void @P_SpawnMobj() {
   ret void
 }
 
-define void @AM_Stop() {
+; CHECK-LABEL: G_PlayerReborn:
+define void @G_PlayerReborn() {
   ret void
 }
 
-define void @D_AdvanceDemo() {
+; CHECK-LABEL: P_SetThingPosition:
+define void @P_SetThingPosition() {
   ret void
 }
 
-define void @F_StartFinale() {
+; CHECK-LABEL: P_SetupPsprites:
+define void @P_SetupPsprites(ptr addrspace(1) %i) {
+  %fptr = load ptr, ptr addrspace(1) %i, align 8
+  tail call void %fptr()
   ret void
 }
 
-define void @F_Ticker() {
+; CHECK-LABEL: HU_Start:
+define void @HU_Start() {
   ret void
 }
 
-define void @G_PlayerReborn() {
+; CHECK-LABEL: P_SpawnPlayer:
+define void @P_SpawnPlayer() {
+  call void @G_PlayerReborn()
+  call void @P_SetThingPosition()
+  call void @P_SetupPsprites(ptr addrspace(1) null)
+  tail call void @HU_Start()
   ret void
 }
 
-define i32 @G_CheckDemoStatus() {
-  tail call void @I_Quit()
-  tail call void @D_AdvanceDemo()
-  call void (...) @I_Error()
-  ret i32 0
-}
-
-define void @HU_Start() {
+; CHECK-LABEL: I_Error:
+define void @I_Error(...) {
+  %fptr = load ptr, ptr null, align 8
+  call void %fptr()
   ret void
 }
 
-define void @I_Quit() {
-  %fptr = load ptr, ptr null, align 8
-  tail call void %fptr()
+; CHECK-LABEL: G_DoReborn:
+define void @G_DoReborn() {
+  call void @P_RemoveMobj()
+  call void @P_SpawnMobj()
+  call void @P_SpawnPlayer()
+  call void (...) @I_Error()
   ret void
 }
 
-define void @P_SetThingPosition() {
+; CHECK-LABEL: AM_Stop:
+define void @AM_Stop() {
   ret void
 }
 
-define void @P_RemoveMobj() {
+; CHECK-LABEL: D_AdvanceDemo:
+define void @D_AdvanceDemo() {
   ret void
 }
 
-define void @P_SpawnMobj() {
+; CHECK-LABEL: F_StartFinale:
+define void @F_StartFinale() {
   ret void
 }
 
-define void @P_SpawnPlayer() {
-  call void @G_PlayerReborn()
-  call void @P_SetThingPosition()
-  call void @P_SetupPsprites(ptr addrspace(1) null)
-  tail call void @HU_Start()
+; CHECK-LABEL: F_Ticker:
+define void @F_Ticker() {
   ret void
 }
 
-define void @P_SetupPsprites(ptr addrspace(1) %i) {
-  %fptr = load ptr, ptr addrspace(1) %i, align 8
-  tail call void %fptr()
-  ret void
+; CHECK-LABEL: G_CheckDemoStatus:
+define i32 @G_CheckDemoStatus() {
+  tail call void @I_Quit()
+  tail call void @D_AdvanceDemo()
+  call void (...) @I_Error()
+  ret i32 0
 }
 
+
+; CHECK-LABEL: P_TempSaveGameFile:
 define ptr @P_TempSaveGameFile() {
   ret ptr null
 }
 
+; CHECK-LABEL: P_SaveGameFile:
 define ptr @P_SaveGameFile() {
   ret ptr null
 }
 
+; CHECK-LABEL: R_FlatNumForName:
+define i32 @R_FlatNumForName() {
+  call void (...) @I_Error()
+  unreachable
+}
+
+; CHECK-LABEL: R_TextureNumForName:
 define i32 @R_TextureNumForName() {
   %ret = call i32 @R_FlatNumForName()
   ret i32 0
 }
 
-define void @I_Error(...) {
-  %fptr = load ptr, ptr null, align 8
-  call void %fptr()
+; CHECK-LABEL: G_Ticker:
+define void @G_Ticker() {
+  call void @G_DoReborn()
+  tail call void @F_Ticker()
+  tail call void @AM_Stop()
+  tail call void @F_StartFinale()
+  tail call void @D_AdvanceDemo()
+  %call.i.i449 = call i32 @R_FlatNumForName()
+  %call9.i.i = call i32 @R_TextureNumForName()
+  %call.i306 = tail call ptr @P_TempSaveGameFile()
+  %call1.i307 = call ptr @P_SaveGameFile()
+  call void (...) @I_Error()
   ret void
 }
 
-define i32 @R_FlatNumForName() {
-  call void (...) @I_Error()
-  unreachable
+; CHECK-LABEL: RunTic:
+define void @RunTic() {
+  %call5.i1 = call i32 @G_CheckDemoStatus()
+  tail call void @D_AdvanceDemo()
+  call void @G_Ticker()
+  ret void
 }
----------------
arsenm wrote:

Check resource limits? 

https://github.com/llvm/llvm-project/pull/111568