Expand -fzero-call-used-regs test to cover gcc 11.

It turns out that gcc also has some problems with -fzero-call-used-regs,
at least v11 on mips.  Previously the test in OSSH_CHECK_CFLAG_COMPILE
was sufficient to catch it with "=all", but not sufficient for "=used".
Expand the testcase and include it in the other tests for good measure.
See bz#3629.  ok djm@.

diff --git a/m4/openssh.m4 b/m4/openssh.m4
index 8c33c701b8b42ee7eef99cdcbaf0c695591fe0b8..e6d392a02ded19a2008844e20a2e965c559c1728 100644 (file)
--- a/m4/openssh.m4
+++ b/m4/openssh.m4
@@ -15,7 +15,7 @@ AC_DEFUN([OSSH_CHECK_CFLAG_COMPILE], [{
 #include <stdlib.h>
 #include <stdio.h>
 /* Trivial function to help test for -fzero-call-used-regs */
-void f(int n) {}
+int f(int n) {return rand() % n;}
 int main(int argc, char **argv) {
        (void)argv;
        /* Some math to catch -ftrapv problems in the toolchain */
@@ -65,6 +65,8 @@ AC_DEFUN([OSSH_CHECK_CFLAG_LINK], [{
        AC_LINK_IFELSE([AC_LANG_SOURCE([[
 #include <stdlib.h>
 #include <stdio.h>
+/* Trivial function to help test for -fzero-call-used-regs */
+int f(int n) {return rand() % n;}
 int main(int argc, char **argv) {
        (void)argv;
        /* Some math to catch -ftrapv problems in the toolchain */
@@ -73,6 +75,7 @@ int main(int argc, char **argv) {
        double m = l / 0.5;
        long long int n = argc * 12345LL, o = 12345LL * (long long int)argc;
        long long int p = n * o;
+       f(0);
        printf("%d %d %d %f %f %lld %lld %lld\n", i, j, k, l, m, n, o, p);
        exit(0);
 }
@@ -104,6 +107,8 @@ AC_DEFUN([OSSH_CHECK_LDFLAG_LINK], [{
        AC_LINK_IFELSE([AC_LANG_SOURCE([[
 #include <stdlib.h>
 #include <stdio.h>
+/* Trivial function to help test for -fzero-call-used-regs */
+int f(int n) {return rand() % n;}
 int main(int argc, char **argv) {
        (void)argv;
        /* Some math to catch -ftrapv problems in the toolchain */
@@ -112,6 +117,7 @@ int main(int argc, char **argv) {
        double m = l / 0.5;
        long long int n = argc * 12345LL, o = 12345LL * (long long int)argc;
        long long p = n * o;
+       f(0);
        printf("%d %d %d %f %f %lld %lld %lld\n", i, j, k, l, m, n, o, p);
        exit(0);
 }