Re: [Tinycc-devel] i386 build of gawk with tcc now broken

[Ramsay Jones]

On 08/09/13 08:00, address@hidden wrote:
>>> After pulling the latest on the mob branch, builds of gawk master using
>>> tcc generate lots of test failures.
>>>
>>> On an i386 linux system:
>>>
>>>     git clone git://git.savannah.gnu.org/gawk.git
>>>     cd gawk
>>>     ./bootstrap.sh && configure CC=tcc && make
>>>     make check      # watch lots of things go kablooey
>>>
>>> This does not occur on x86-64.
>>
>> Does this also happen with tcc 0.9.26 and tcc 0.9.25 or just with the mob 
>> branch?
> 
> I'm pretty sure just the mob branch. I can double check tomorrow
> when I'm at the machine. Almost all the errors are related to floating
> point exceptions; I strongly suspect it has to do with the most recent
> changes.
> 
> The recipe above will let you reproduce it a lot quicker than waiting
> for me...
> 
> 0.9.25 won't be worth checking as it's tool old, FWIW.

I have a patch to fix the tests, which fail for me with a Floating
point exception:

    address@hidden $ make test
    :
    [snip]
    :
    ------------ test3 ------------
    ../tcc -B.. -I.. -I.. -I../include -DCONFIG_LDDIR="\"lib/i386-linux-gnu\""
    -DCONFIG_MULTIARCHDIR="\"i386-linux-gnu\"" -DTCC_TARGET_I386 -DONE_SOURCE 
-run
    ../tcc.c -B.. -I.. -I.. -I../include -DCONFIG_LDDIR="\"lib/i386-linux-gnu\""
    -DCONFIG_MULTIARCHDIR="\"i386-linux-gnu\"" -DTCC_TARGET_I386 -DONE_SOURCE 
-run
    ../tcc.c -B.. -I.. -I.. -I../include -DCONFIG_LDDIR="\"lib/i386-linux-gnu\""
    -DCONFIG_MULTIARCHDIR="\"i386-linux-gnu\"" -DTCC_TARGET_I386 -DONE_SOURCE 
-run
    ../tcc.c -B.. -I.. -I.. -I../include -run ../tests/tcctest.c > test.out3
    Floating point exception
    make[1]: *** [test3] Error 136
    make[1]: Leaving directory `/home/ramsay/tinycc/tests'
    make: *** [test] Error 2
    address@hidden $ 

If you run 'git bisect' you will find the culprit is commit 73faaea2
("i386-gen: preserve fp control word in gen_cvt_ftoi", 28-08-2013).

Try the following patch and let me know if it fixes it up for you.

ATB,
Ramsay Jones

--- 8< ---
From: Ramsay Jones <address@hidden>
Date: Sat, 7 Sep 2013 22:48:02 +0100
Subject: [PATCH] libtcc1.c: Fix __asm__() in __tcc_fpinit and __tcc_cvt_ftol

Signed-off-by: Ramsay Jones <address@hidden>
---
 lib/libtcc1.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/libtcc1.c b/lib/libtcc1.c
index a94a82d..a717701 100644
--- a/lib/libtcc1.c
+++ b/lib/libtcc1.c
@@ -482,7 +482,7 @@ long long __ashldi3(long long a, int b)
 void __tcc_fpinit(void)
 {
     unsigned c = 0x137F;
-    __asm__ __volatile__ ("fldcw %0" : "=m" (c));
+    __asm__ __volatile__ ("fldcw %0" : : "m" (c));
 }
 #endif
 long long __tcc_cvt_ftol(long double x)
@@ -491,9 +491,9 @@ long long __tcc_cvt_ftol(long double x)
     long long ret;
     __asm__ __volatile__ ("fnstcw %0" : "=m" (c0));
     c1 = c0 | 0x0C00;
-    __asm__ __volatile__ ("fldcw %0" : "=m" (c1));
+    __asm__ __volatile__ ("fldcw %0" : : "m" (c1));
     __asm__ __volatile__ ("fistpll %0"  : "=m" (ret));
-    __asm__ __volatile__ ("fldcw %0" : "=m" (c0));
+    __asm__ __volatile__ ("fldcw %0" : : "m" (c0));
     return ret;
 }
 #endif /* !__x86_64__ */
-- 
1.8.4