Improve detection of -fzero-call-used-regs=all support

GCC doesn't tell us whether this option is supported unless it runs into
the situation where it would need to emit corresponding code.
This commit is contained in:
Colin Watson 2022-02-24 16:04:18 +00:00 committed by Damien Miller
parent 3383b2cac0
commit f107467179
1 changed files with 3 additions and 0 deletions

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@ -14,6 +14,8 @@ AC_DEFUN([OSSH_CHECK_CFLAG_COMPILE], [{
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#include <stdlib.h>
#include <stdio.h>
/* Trivial function to help test for -fzero-call-used-regs */
void f(int n) {}
int main(int argc, char **argv) {
(void)argv;
/* Some math to catch -ftrapv problems in the toolchain */
@ -21,6 +23,7 @@ int main(int argc, char **argv) {
float l = i * 2.1;
double m = l / 0.5;
long long int n = argc * 12345LL, o = 12345LL * (long long int)argc;
f(0);
printf("%d %d %d %f %f %lld %lld\n", i, j, k, l, m, n, o);
/*
* Test fallthrough behaviour. clang 10's -Wimplicit-fallthrough does