[CodeGenPrepare] Don't give up if unable to sink first arg to a cold call

[nikic]

llvm/test/CodeGen/Generic/addr-sink-call-multi-arg.ll

1

Can we make this an opt -codegenprepare test instead and use update_test_checks? (Applies to the rest of this patch stack as well.)

7

i32 * should be ptr as well.

[mkazantsev]

Code change LG, please address Nikita's comments before checking in the test.

[chill]

llvm/test/CodeGen/Generic/addr-sink-call-multi-arg.ll

7

Will do.

llvm/lib/CodeGen/CodeGenPrepare.cpp

bool CodeGenPrepare::optimizeCallInst(CallInst *CI, ModifyDT &ModifiedDT) {
   // ensure that we can fold all uses of a potential addressing computation
   // into their uses.  TODO: generalize this to work over profiling data
   if (CI->hasFnAttr(Attribute::Cold) && !OptSize &&
       !llvm::shouldOptimizeForSize(BB, PSI, BFI.get()))
     for (auto &Arg : CI->args()) {
       if (!Arg->getType()->isPointerTy())
         continue;
       unsigned AS = Arg->getType()->getPointerAddressSpace();
-      return optimizeMemoryInst(CI, Arg, Arg->getType(), AS);
+      if (optimizeMemoryInst(CI, Arg, Arg->getType(), AS))
+        return true;
     }
 
   IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI);
   if (II) {
     switch (II->getIntrinsicID()) {
     default:
       break;
     case Intrinsic::assume:

llvm/test/CodeGen/Generic/addr-sink-call-multi-arg.ll

+; RUN: llc --stop-after=codegenprepare < %s | FileCheck %s
+
+declare void @f(ptr, ptr) cold
+
+define void @g(i1 %c1, ptr %p, i32 %i) {
+entry:
+    %a0 = getelementptr i32 *, ptr %p, i32 %i
+    %a1 = getelementptr i32 *, ptr %p, i32 4
+    br i1 %c1, label %if.then, label %exit
+
+if.then:
+; Check that we don't give up on the first argument.
+; CHECK:  %sunkaddr = getelementptr i8, ptr %p, i64 32
+; CHECK:  call void @f(ptr %a0, ptr %sunkaddr)
+    call void @f(ptr %a0, ptr %a1)
+    br label %exit
+
+exit:
+    ret void
+}