Merge pull request #76078 from kavon/coldsplit-1

ColdSplit: avoid with -Osize

Author: kavon

lib/IRGen/IRGen.cpp

@@ -222,7 +222,8 @@ void swift::performLLVMOptimizations(const IRGenOptions &Opts,
     PTO.LoopVectorization = true;
     PTO.SLPVectorization = true;
     PTO.MergeFunctions = true;
-    DoHotColdSplit = Opts.EnableHotColdSplit;
+    // Splitting trades code size to enhance memory locality, avoid in -Osize.
+    DoHotColdSplit = Opts.EnableHotColdSplit && !Opts.optimizeForSize();
     level = llvm::OptimizationLevel::Os;
   } else {
     level = llvm::OptimizationLevel::O0;

test/IRGen/cold_split.swift

@@ -7,6 +7,11 @@
 // RUN:   -enable-throws-prediction -O -disable-split-cold-code \
 // RUN:       | %FileCheck --check-prefix CHECK-DISABLED %s
 
+//// Test using -Osize doesn't yield a split.
+// RUN: %target-swift-frontend %s -module-name=test -emit-assembly \
+// RUN:   -enable-throws-prediction -Osize -enable-split-cold-code \
+// RUN:       | %FileCheck --check-prefix CHECK-DISABLED %s
+
 //// Test disabling optimization entirely doesn't yield a split.
 // RUN: %target-swift-frontend %s -module-name=test -emit-assembly \
 // RUN:   -enable-throws-prediction -enable-split-cold-code \