[ARM] Prefer indirect calls in minsize mode
... When we emit several calls to the same function in the same basic block.
An indirect call uses a "BLX r0" instruction which has a 16-bit encoding. If many calls are made to the same target, this can enable significant code size reductions.
llvm-svn: 275537
diff --git a/llvm/test/CodeGen/ARM/minsize-call-cse.ll b/llvm/test/CodeGen/ARM/minsize-call-cse.ll
new file mode 100644
index 0000000..072b76f
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/minsize-call-cse.ll
@@ -0,0 +1,28 @@
+; RUN: llc < %s | FileCheck %s
+
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+target triple = "thumbv7m-arm-none-eabi"
+
+; CHECK-LABEL: f:
+; CHECK: blx r
+; CHECK: blx r
+; CHECK: blx r
+define void @f() minsize optsize {
+entry:
+ call void @g(i32 45, i32 66)
+ call void @g(i32 88, i32 32)
+ call void @g(i32 55, i32 33)
+ ret void
+}
+
+; CHECK-LABEL: h:
+; CHECK: bl g
+; CHECK: bl g
+define void @h() minsize optsize {
+entry:
+ call void @g(i32 45, i32 66)
+ call void @g(i32 88, i32 32)
+ ret void
+}
+
+declare void @g(i32,i32)