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authorUlrich Drepper <drepper@redhat.com>2004-07-20 07:04:32 +0000
committerUlrich Drepper <drepper@redhat.com>2004-07-20 07:04:32 +0000
commitc747e725e310d16c40aa815ed9e3e9f2805351e7 (patch)
tree1c1e5b3392dc7a91bb4163503350daf91cda29c5 /sysdeps/i386/fpu/e_powf.S
parentb27e7a54576ba9aa47a2c8d630084c41c502479a (diff)
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(__ieee754_powf): Don't generate invalid exception if |y| >= 1U<<31.
Diffstat (limited to 'sysdeps/i386/fpu/e_powf.S')
-rw-r--r--sysdeps/i386/fpu/e_powf.S13
1 files changed, 12 insertions, 1 deletions
diff --git a/sysdeps/i386/fpu/e_powf.S b/sysdeps/i386/fpu/e_powf.S
index dce81697db..b3fa624f4d 100644
--- a/sysdeps/i386/fpu/e_powf.S
+++ b/sysdeps/i386/fpu/e_powf.S
@@ -1,5 +1,5 @@
 /* ix87 specific implementation of pow function.
-   Copyright (C) 1996, 1997, 1999, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1996, 1997, 1999, 2001, 2004 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
 
@@ -48,6 +48,9 @@ one:	.double 1.0
 	ASM_TYPE_DIRECTIVE(limit,@object)
 limit:	.double 0.29
 	ASM_SIZE_DIRECTIVE(limit)
+	ASM_TYPE_DIRECTIVE(p31,@object)
+p31:	.byte 0, 0, 0, 0, 0, 0, 0xe0, 0x41
+	ASM_SIZE_DIRECTIVE(p31)
 
 #ifdef PIC
 #define MO(op) op##@GOTOFF(%ecx)
@@ -96,6 +99,14 @@ ENTRY(__ieee754_powf)
 
 	fxch			// y : x
 
+	/* fistpl raises invalid exception for |y| >= 1L<<31.  */
+	fld	%st		// y : y : x
+	fabs			// |y| : y : x
+	fcompl	MO(p31)		// y : x
+	fnstsw
+	sahf
+	jnc	2f
+
 	/* First see whether `y' is a natural number.  In this case we
 	   can use a more precise algorithm.  */
 	fld	%st		// y : y : x