Improve 64-subtraction of immediates when parts of the immediate can fit
in the literal field of an instruction. E.g.,
long long foo(long long a) {
return a - 734439407618LL;
}
rdar://7038284
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108339 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/ARM/sub.ll b/test/CodeGen/ARM/sub.ll
new file mode 100644
index 0000000..81513e2
--- /dev/null
+++ b/test/CodeGen/ARM/sub.ll
@@ -0,0 +1,29 @@
+; RUN: llc -march=arm < %s | FileCheck %s
+
+; 171 = 0x000000ab
+define i64 @f1(i64 %a) {
+; CHECK: f1
+; CHECK: subs r0, r0, #171
+; CHECK: sbc r1, r1, #0
+ %tmp = sub i64 %a, 171
+ ret i64 %tmp
+}
+
+; 66846720 = 0x03fc0000
+define i64 @f2(i64 %a) {
+; CHECK: f2
+; CHECK: subs r0, r0, #255, 14
+; CHECK: sbc r1, r1, #0
+ %tmp = sub i64 %a, 66846720
+ ret i64 %tmp
+}
+
+; 734439407618 = 0x000000ab00000002
+define i64 @f3(i64 %a) {
+; CHECK: f3
+; CHECK: subs r0, r0, #2
+; CHECK: sbc r1, r1, #171
+ %tmp = sub i64 %a, 734439407618
+ ret i64 %tmp
+}
+