fix minsize detection: minsize attribute implies optimizing for size

llvm-svn: 244528

2 files changed, 39 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp
index f2d1bf0a51f..260ab537053 100644
--- a/llvm/lib/CodeGen/BranchFolding.cpp
+++ b/llvm/lib/CodeGen/BranchFolding.cpp
@@ -605,9 +605,7 @@ static bool ProfitableToMerge(MachineBasicBlock *MBB1,
   // branch instruction, which is likely to be smaller than the 2
   // instructions that would be deleted in the merge.
   MachineFunction *MF = MBB1->getParent();
-  if (EffectiveTailLen >= 2 &&
-      // FIXME: Use Function::optForSize().
-      MF->getFunction()->hasFnAttribute(Attribute::OptimizeForSize) &&
+  if (EffectiveTailLen >= 2 && MF->getFunction()->optForSize() &&
       (I1 == MBB1->begin() || I2 == MBB2->begin()))
     return true;
 
diff --git a/llvm/test/CodeGen/X86/tail-opts.ll b/llvm/test/CodeGen/X86/tail-opts.ll
index f590176d981..c522ba60d6b 100644
--- a/llvm/test/CodeGen/X86/tail-opts.ll
+++ b/llvm/test/CodeGen/X86/tail-opts.ll
@@ -371,6 +371,44 @@ return:
   ret void
 }
 
+; two_minsize - Same as two, but with minsize instead of optsize.
+
+; CHECK-LABEL: two_minsize:
+; CHECK-NOT: XYZ
+; CHECK: ret
+; CHECK: movl $0, XYZ(%rip)
+; CHECK: movl $1, XYZ(%rip)
+; CHECK-NOT: XYZ
+
+define void @two_minsize() nounwind minsize {
+entry:
+  %0 = icmp eq i32 undef, 0
+  br i1 %0, label %bbx, label %bby
+
+bby:
+  switch i32 undef, label %bb7 [
+    i32 16, label %return
+  ]
+
+bb7:
+  store volatile i32 0, i32* @XYZ
+  store volatile i32 1, i32* @XYZ
+  unreachable
+
+bbx:
+  switch i32 undef, label %bb12 [
+    i32 128, label %return
+  ]
+
+bb12:
+  store volatile i32 0, i32* @XYZ
+  store volatile i32 1, i32* @XYZ
+  unreachable
+
+return:
+  ret void
+}
+
 ; two_nosize - Same as two, but without the optsize attribute.
 ; Now two instructions are enough to be tail-duplicated.