Silence illegal address computation warning (#83244)

Martin Wehking · web-flow · commit 92fe6c61f900 · 2024-03-01T21:41:12.000+05:30
Add an assertion before an access of ValMappings to ensure that it is
within the array bounds.
Silence a static analyzer warning through this.
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUGenRegisterBankInfo.def b/llvm/lib/Target/AMDGPU/AMDGPUGenRegisterBankInfo.def
@@ -284,6 +284,7 @@ const RegisterBankInfo::ValueMapping *getValueMapping(unsigned BankID,
     break;
   }
 
+  assert(Idx < std::size(ValMappings));
   assert(Log2_32_Ceil(Size) == Log2_32_Ceil(ValMappings[Idx].BreakDown->Length));
   assert(BankID == ValMappings[Idx].BreakDown->RegBank->getID());
 

Original file line number	Diff line number	Diff line change
`@@ -284,6 +284,7 @@ const RegisterBankInfo::ValueMapping *getValueMapping(unsigned BankID,`
`284`	`284`	`break;`
`285`	`285`	`}`
`286`	`286`
	`287`	`+ assert(Idx < std::size(ValMappings));`
`287`	`288`	`assert(Log2_32_Ceil(Size) == Log2_32_Ceil(ValMappings[Idx].BreakDown->Length));`
`288`	`289`	`assert(BankID == ValMappings[Idx].BreakDown->RegBank->getID());`
`289`	`290`