With some recent optimization, -O1/-O2/-O3 can archive almost same
performace/size by stack load/store. Thus lwm/swm will save/store
less callee-saved register. In fact only $16 is saved with swm.
To be sure that this optimization does exist, let's add 2 more
function calls. So that lwm/swm can be much more profitable.
If we add only once more, -O1 will still use stack load/store.
gcc/testsuite
* gcc.target/mips/umips-save-restore-1.c: Be sure lwm/swm
are used for more callee-saved registers with addtional
2 more function calls.
---
gcc/testsuite/gcc.target/mips/umips-save-restore-1.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/gcc/testsuite/gcc.target/mips/umips-save-restore-1.c
b/gcc/testsuite/gcc.target/mips/umips-save-restore-1.c
index ff1ea4b339a..0e2c4dcc844 100644
--- a/gcc/testsuite/gcc.target/mips/umips-save-restore-1.c
+++ b/gcc/testsuite/gcc.target/mips/umips-save-restore-1.c
@@ -7,12 +7,14 @@ int bar (int, int, int, int, int);
MICROMIPS int
foo (int n, int a, int b, int c, int d)
{
- int i, j;
+ int i, j, k, l;
i = bar (n, a, b, c, d);
j = bar (n, a, b, c, d);
- return i + j;
+ k = bar (n, a, b, c, d);
+ l = bar (n, a, b, c, d);
+ return i + j + k + l;
}
-/* { dg-final { scan-assembler "\tswm\t\\\$16-\\\$2(0|1),\\\$31" } } */
-/* { dg-final { scan-assembler "\tlwm\t\\\$16-\\\$2(0|1),\\\$31" } } */
+/* { dg-final { scan-assembler "\tswm\t\\\$16-\\\$2(2|3),\\\$31" } } */
+/* { dg-final { scan-assembler "\tlwm\t\\\$16-\\\$2(2|3),\\\$31" } } */
--
2.39.3 (Apple Git-146)
