[ARM] icmp %x, -C can be lowered to a simple ADDS or CMN

Tell TargetTransformInfo about this so ConstantHoisting is informed.

llvm-svn: 281043

1 files changed, 34 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/ARM/immcost.ll b/llvm/test/CodeGen/ARM/immcost.ll
index bfc1fddd3c1..43a4989e6bd 100644
--- a/llvm/test/CodeGen/ARM/immcost.ll
+++ b/llvm/test/CodeGen/ARM/immcost.ll
@@ -37,3 +37,37 @@ ret:
   ret void
 }
 
+; CHECK: Function: test_icmp_neg
+; CHECK-NOT: Collect constant
+define void @test_icmp_neg(i1 %cond, i32 %arg, i32 %arg2) {
+entry:
+  %a = icmp ne i32 %arg, -5
+  call void @g2(i1 %a)
+  br i1 %cond, label %true, label %ret
+
+true:
+  %b = icmp ne i32 %arg2, -5
+  call void @g2(i1 %b)
+  br label %ret
+
+ret:
+  ret void
+}
+declare void @g2(i1)
+
+; CHECK: Function: test_icmp_neg2
+; CHECK: Hoist constant (i32 -500) to BB entry
+define void @test_icmp_neg2(i1 %cond, i32 %arg, i32 %arg2) {
+entry:
+  %a = icmp ne i32 %arg, -500
+  call void @g2(i1 %a)
+  br i1 %cond, label %true, label %ret
+
+true:
+  %b = icmp ne i32 %arg2, -500
+  call void @g2(i1 %b)
+  br label %ret
+
+ret:
+  ret void
+}