[SPIRV] Avoid repeated map lookups (NFC) (#128129)

kazutakahirata · web-flow · commit 8c1207bee3c6 · 2025-02-21T11:08:30.000-08:00
diff --git a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h
@@ -176,8 +176,9 @@ struct ModuleAnalysisInfo {
     RegisterAliasTable[MF][Reg] = AliasReg;
   }
   Register getRegisterAlias(const MachineFunction *MF, Register Reg) {
-    auto RI = RegisterAliasTable[MF].find(Reg);
-    if (RI == RegisterAliasTable[MF].end()) {
+    auto &RegTable = RegisterAliasTable[MF];
+    auto RI = RegTable.find(Reg);
+    if (RI == RegTable.end()) {
       return Register(0);
     }
     return RI->second;

Original file line number	Diff line number	Diff line change
`@@ -176,8 +176,9 @@ struct ModuleAnalysisInfo {`
`176`	`176`	`RegisterAliasTable[MF][Reg] = AliasReg;`
`177`	`177`	`}`
`178`	`178`	`Register getRegisterAlias(const MachineFunction *MF, Register Reg) {`
`179`		`- auto RI = RegisterAliasTable[MF].find(Reg);`
`180`		`- if (RI == RegisterAliasTable[MF].end()) {`
	`179`	`+ auto &RegTable = RegisterAliasTable[MF];`
	`180`	`+ auto RI = RegTable.find(Reg);`
	`181`	`+ if (RI == RegTable.end()) {`
`181`	`182`	`return Register(0);`
`182`	`183`	`}`
`183`	`184`	`return RI->second;`