This test uses a call-saved register as a global variable. It
attempts to preserve its value across main, but only the lower int
part is preserved, which is not good enough for x86_64, when the
runtime that calls main() happens to hold something in the chosen
register that is not a zero-extension from the 32-bit value, and
rightfully expects the full register to remain unchanged when main()
returns.
Tested on x86_64-linux-gnu, both -m64 and -m32. Ok to install?
for gcc/testsuite/ChangeLog
* gcc.target/i386/20020616-1.c: Preserve full register across
main.
---
gcc/testsuite/gcc.target/i386/20020616-1.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/gcc/testsuite/gcc.target/i386/20020616-1.c
b/gcc/testsuite/gcc.target/i386/20020616-1.c
index 5641826b4837..3b8cf8e41783 100644
--- a/gcc/testsuite/gcc.target/i386/20020616-1.c
+++ b/gcc/testsuite/gcc.target/i386/20020616-1.c
@@ -2,12 +2,16 @@
/* { dg-do run } */
/* { dg-options "-O2" } */
+/* We need this type to be as wide as the register chosen below, so
+ that, when we preserve it across main, we preserve all of it. */
+typedef long reg_type;
+
#if !__PIC__
-register int k asm("%ebx");
+register reg_type k asm("%ebx");
#elif __amd64
-register int k asm("%r12");
+register reg_type k asm("%r12");
#else
-register int k asm("%esi");
+register reg_type k asm("%esi");
#endif
void __attribute__((noinline))
@@ -18,7 +22,7 @@ foo()
void test()
{
- int i;
+ reg_type i;
for (i = 0; i < 10; i += k)
{
k = 0;
@@ -28,7 +32,7 @@ void test()
int main()
{
- int old = k;
+ reg_type old = k;
test();
k = old;
return 0;
--
Alexandre Oliva, freedom fighter he/him https://FSFLA.org/blogs/lxo
Be the change, be Free! FSF Latin America board member
GNU Toolchain Engineer Free Software Evangelist
Hay que enGNUrecerse, pero sin perder la terGNUra jamás - Che GNUevara
