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[PATCH] Fix overflow handling for expm1/expm1f/expm1l on x86
- From: Andreas Schwab <schwab at redhat dot com>
- To: libc-alpha at sourceware dot org
- Date: Mon, 19 Oct 2009 18:10:33 +0200
- Subject: [PATCH] Fix overflow handling for expm1/expm1f/expm1l on x86
- References: <m3zl7nfnyi.fsf@hase.home>
This is an extended patch (superseding the last one) to also fix the
failures for expm1 and expm1f.
Andreas.
2009-10-19 Andreas Schwab <schwab@redhat.com>
* include/math.h: Add hidden protos for __exp/__expf/__expl.
* sysdeps/ieee754/dbl-64/w_exp.c: Add hidden alias.
* sysdeps/ieee754/flt-32/w_expf.c: Likewise.
* sysdeps/ieee754/ldbl-96/w_expl.c: Likewise.
* sysdeps/i386/fpu/s_expm1.S: Call __exp to handle overflow.
* sysdeps/i386/fpu/s_expm1f.S: Call __expf to handle overflow.
* sysdeps/i386/fpu/s_expm1l.S: Call __expl instead of
__ieee751_expl to handle overflow.
diff --git a/include/math.h b/include/math.h
index 1005804..eb29ef1 100644
--- a/include/math.h
+++ b/include/math.h
@@ -22,9 +22,12 @@ hidden_proto (__isnanl)
libm_hidden_proto (__fpclassify)
libm_hidden_proto (__fpclassifyf)
+libm_hidden_proto (__exp)
+libm_hidden_proto (__expf)
# ifndef __NO_LONG_DOUBLE_MATH
libm_hidden_proto (__fpclassifyl)
+libm_hidden_proto (__expl)
libm_hidden_proto (__expm1l)
# endif
diff --git a/sysdeps/i386/fpu/s_expm1.S b/sysdeps/i386/fpu/s_expm1.S
index e761183..c690a45 100644
--- a/sysdeps/i386/fpu/s_expm1.S
+++ b/sysdeps/i386/fpu/s_expm1.S
@@ -22,6 +22,7 @@
/* Using: e^x - 1 = 2^(x * log2(e)) - 1 */
+#include <sysdep.h>
#include <machine/asm.h>
#ifdef __ELF__
@@ -48,6 +49,11 @@ l2e: .tfloat 1.442695040888963407359924681002
.text
ENTRY(__expm1)
+ movzwl 4+6(%esp), %eax
+ xorb $0x80, %ah // invert sign bit (now 1 is "positive")
+ cmpl $0xc086, %eax // is num >= 704?
+ jae HIDDEN_JUMPTARGET (__exp)
+
fldl 4(%esp) // x
fxam // Is NaN or +-Inf?
fstsw %ax
diff --git a/sysdeps/i386/fpu/s_expm1f.S b/sysdeps/i386/fpu/s_expm1f.S
index 88adb75..8645107 100644
--- a/sysdeps/i386/fpu/s_expm1f.S
+++ b/sysdeps/i386/fpu/s_expm1f.S
@@ -22,6 +22,7 @@
/* Using: e^x - 1 = 2^(x * log2(e)) - 1 */
+#include <sysdep.h>
#include <machine/asm.h>
#ifdef __ELF__
@@ -48,6 +49,11 @@ l2e: .tfloat 1.442695040888963407359924681002
.text
ENTRY(__expm1f)
+ movzwl 4+2(%esp), %eax
+ xorb $0x80, %ah // invert sign bit (now 1 is "positive")
+ cmpl $0xc2b1, %eax // is num >= 88.5?
+ jae HIDDEN_JUMPTARGET (__expf)
+
flds 4(%esp) // x
fxam // Is NaN or +-Inf?
fstsw %ax
diff --git a/sysdeps/i386/fpu/s_expm1l.S b/sysdeps/i386/fpu/s_expm1l.S
index b69b22b..60b5b82 100644
--- a/sysdeps/i386/fpu/s_expm1l.S
+++ b/sysdeps/i386/fpu/s_expm1l.S
@@ -22,6 +22,7 @@
/* Using: e^x - 1 = 2^(x * log2(e)) - 1 */
+#include <sysdep.h>
#include <machine/asm.h>
#ifdef __ELF__
@@ -51,7 +52,7 @@ ENTRY(__expm1l)
movzwl 4+8(%esp), %eax // load sign bit and 15-bit exponent
xorb $0x80, %ah // invert sign bit (now 1 is "positive")
cmpl $0xc006, %eax // is num positive and exp >= 6 (number is >= 128.0)?
- jae __ieee754_expl // (if num is denormal, it is at least >= 64.0)
+ jae HIDDEN_JUMPTARGET (__expl) // (if num is denormal, it is at least >= 64.0)
fldt 4(%esp) // x
fxam // Is NaN or +-Inf?
diff --git a/sysdeps/ieee754/dbl-64/w_exp.c b/sysdeps/ieee754/dbl-64/w_exp.c
index 445c578..1216492 100644
--- a/sysdeps/ieee754/dbl-64/w_exp.c
+++ b/sysdeps/ieee754/dbl-64/w_exp.c
@@ -51,6 +51,7 @@ u_threshold= -7.45133219101941108420e+02; /* 0xc0874910, 0xD52D3051 */
return z;
#endif
}
+hidden_def (__exp)
weak_alias (__exp, exp)
#ifdef NO_LONG_DOUBLE
strong_alias (__exp, __expl)
diff --git a/sysdeps/ieee754/flt-32/w_expf.c b/sysdeps/ieee754/flt-32/w_expf.c
index 4ba21c7..83b268f 100644
--- a/sysdeps/ieee754/flt-32/w_expf.c
+++ b/sysdeps/ieee754/flt-32/w_expf.c
@@ -56,4 +56,5 @@ u_threshold= -1.0397208405e+02; /* 0xc2cff1b5 */
return z;
#endif
}
+hidden_def (__expf)
weak_alias (__expf, expf)
diff --git a/sysdeps/ieee754/ldbl-96/w_expl.c b/sysdeps/ieee754/ldbl-96/w_expl.c
index b8152ce..53bb143 100644
--- a/sysdeps/ieee754/ldbl-96/w_expl.c
+++ b/sysdeps/ieee754/ldbl-96/w_expl.c
@@ -57,4 +57,5 @@ u_threshold= -1.140019167866942050398521670162263001513e4;
return z;
#endif
}
+hidden_def (__expl)
weak_alias (__expl, expl)
--
1.6.5.1
--
Andreas Schwab, schwab@redhat.com
GPG Key fingerprint = D4E8 DBE3 3813 BB5D FA84 5EC7 45C6 250E 6F00 984E
"And now for something completely different."