From 3f2aacafdc2e8172de64e7aa47f7e9cec631b53c Mon Sep 17 00:00:00 2001 From: Daniel Jacobowitz Date: Mon, 15 Sep 2003 20:14:39 +0000 Subject: [PATCH] * floatformat.c (floatformat_is_valid): New function. (get_field, put_field): Correct comments. --- libiberty/ChangeLog | 5 +++++ libiberty/floatformat.c | 39 ++++++++++++++++++++++++++++++++++++--- 2 files changed, 41 insertions(+), 3 deletions(-) diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog index e702593c60..a70872eea1 100644 --- a/libiberty/ChangeLog +++ b/libiberty/ChangeLog @@ -1,3 +1,8 @@ +2003-09-15 Daniel Jacobowitz + + * floatformat.c (floatformat_is_valid): New function. + (get_field, put_field): Correct comments. + 2003-09-06 Josef Zlomek * fibheap.c (fibheap_replace_key_data): Change type of OKEY to diff --git a/libiberty/floatformat.c b/libiberty/floatformat.c index d69024f739..b892dbea40 100644 --- a/libiberty/floatformat.c +++ b/libiberty/floatformat.c @@ -1,5 +1,5 @@ /* IEEE floating point support routines, for GDB, the GNU Debugger. - Copyright (C) 1991, 1994, 1999, 2000 Free Software Foundation, Inc. + Copyright (C) 1991, 1994, 1999, 2000, 2003 Free Software Foundation, Inc. This file is part of GDB. @@ -149,7 +149,7 @@ static unsigned long get_field PARAMS ((unsigned char *, unsigned int, unsigned int)); -/* Extract a field which starts at START and is LEN bytes long. DATA and +/* Extract a field which starts at START and is LEN bits long. DATA and TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */ static unsigned long get_field (data, order, total_len, start, len) @@ -273,7 +273,7 @@ static void put_field PARAMS ((unsigned char *, enum floatformat_byteorders, unsigned int, unsigned long)); -/* Set a field which starts at START and is LEN bytes long. DATA and +/* Set a field which starts at START and is LEN bits long. DATA and TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */ static void put_field (data, order, total_len, start, len, stuff_to_put) @@ -404,6 +404,39 @@ floatformat_from_double (fmt, from, to) } } +/* Return non-zero iff the data at FROM is a valid number in format FMT. */ + +int +floatformat_is_valid (fmt, from) + const struct floatformat *fmt; + char *from; +{ + if (fmt == &floatformat_i387_ext) + { + /* In the i387 double-extended format, if the exponent is all + ones, then the integer bit must be set. If the exponent + is neither 0 nor ~0, the intbit must also be set. Only + if the exponent is zero can it be zero, and then it must + be zero. */ + unsigned long exponent, int_bit; + unsigned char *ufrom = (unsigned char *) from; + + exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize, + fmt->exp_start, fmt->exp_len); + int_bit = get_field (ufrom, fmt->byteorder, fmt->totalsize, + fmt->man_start, 1); + + if ((exponent == 0) != (int_bit == 0)) + return 0; + else + return 1; + } + + /* Other formats with invalid representations should be added + here. */ + return 1; +} + #ifdef IEEE_DEBUG -- 2.34.1