Hello,
I have noticed a build failure with GCC-4.5.0, when configuring with:
--build=x86_64-unknown-linux-gnu
--host=arm-none-linux-gnueabi
--target=arm-none-linux-gnueabi
The build fails when compiling gcc/genconstants.c for the build machine:
In file included from ../../gcc/rtl.h:28,
from ../../gcc/genconstants.c:32:
../../gcc/real.h:84: error: size of array `test_real_width' is negative
I have looked a bit at real.h, and tried to compile with -m32, which works.
Now, I think it should also work without -m32.
From my brief investigation, I think that the problem is due to the
fact that struct real_value uses the 'long' type for the 'sig' field,
while the computation of REAL_WIDTH relies on HOST_BITS_PER_WIDE_INT.
Promoting 'sig' to type unsigned HOST_WIDE_INT makes the compilation pass.
Here is a naive patch proposal:
--- gcc-4.5.0/gcc/real.h 2010-01-05 18:14:30.000000000 +0100
+++ gcc-4.5.0.patched/gcc/real.h 2010-08-06 14:02:03.000000000 +0200
@@ -40,11 +40,11 @@ enum real_value_class {
rvc_nan
};
-#define SIGNIFICAND_BITS (128 + HOST_BITS_PER_LONG)
+#define SIGNIFICAND_BITS (128 + HOST_BITS_PER_WIDE_INT)
#define EXP_BITS (32 - 6)
#define MAX_EXP ((1 << (EXP_BITS - 1)) - 1)
-#define SIGSZ (SIGNIFICAND_BITS / HOST_BITS_PER_LONG)
-#define SIG_MSB ((unsigned long)1 <<
(HOST_BITS_PER_LONG - 1))
+#define SIGSZ (SIGNIFICAND_BITS / HOST_BITS_PER_WIDE_INT)
+#define SIG_MSB ((unsigned HOST_WIDE_INT)1 <<
(HOST_BITS_PER_WIDE_INT - 1))
struct GTY(()) real_value {
/* Use the same underlying type for all bit-fields, so as to make
@@ -56,7 +56,7 @@ struct GTY(()) real_value {
unsigned int signalling : 1;
unsigned int canonical : 1;
unsigned int uexp : EXP_BITS;
- unsigned long sig[SIGSZ];
+ unsigned HOST_WIDE_INT sig[SIGSZ];
};
Is it OK?
Thanks,
Christophe.
