[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH] 64-bit dtoa - strtod fix
From: |
Christian Thalinger |
Subject: |
[PATCH] 64-bit dtoa - strtod fix |
Date: |
Sun, 11 Jan 2004 17:28:23 +0100 |
We are building a java jit called cacao
(http://www.complang.tuwien.ac.at/java/cacao/) which now uses the gnu
classpath. On our 64-bit ports we had problems with dtoa and strtod
functions. After a long night of debugging, i found the problem: it
seems that in mprec.h
#define MAX_BIGNUM_WDS 32
is too small for some floats. The amount can grow up to 48, as my
debugging showed. On i386 systems where Pack_32 is defined, it seems to
be ok. But Pack_32 does not work on 64-bit systems.
This bug is hit, when you try to execute this small code
class test {
public static void main(String[] argv) {
System.out.println(Double.MIN_VALUE);
}
}
with gij (gcc-3.3.2) on x86_64. Defining
#define MAX_BIGNUM_WDS 64
shows the expected result with our jit. I don't know if 64 is a
reasonable number, but when not packing 32-bit in a long but 16-bit,
twice as much should be ok.
This is also cross-posted to address@hidden
TWISTI
--- classpath-0.07/native/fdlibm/mprec.h 2001-11-05
03:56:47.000000000 +0100
+++ cacaodev/gnuclasspath/native/fdlibm/mprec.h 2004-01-11
17:17:55.000000000 +0100
@@ -295,7 +298,12 @@
#define MAX_BIGNUMS 16
+
+#ifndef Pack_32
+#define MAX_BIGNUM_WDS 64
+#else
#define MAX_BIGNUM_WDS 32
+#endif
struct _Jv_Bigint
{
- [PATCH] 64-bit dtoa - strtod fix,
Christian Thalinger <=