From 38aa393e8acbf0d05d704e48694873d4b351ea3d Mon Sep 17 00:00:00 2001
From: Quincey Koziol <koziol@hdfgroup.org>
Date: Mon, 23 Jun 2003 09:22:19 -0500
Subject: [svn-r7084] Purpose:     Bug fix

Description:
    Alignment on Cray SV1 machine was not being detected correctly and was
not aligning integer types correctly for type conversion, nor was detecting the
proper internal offset of the data in a 'short' type.

Solution:
    Added more checks to detect way Cray aligns pointers in addition to current
checks.

    Corrected 'offset' detection on big-endian machines.

Platforms tested:
    FreeBSD 4.8 (sleipnir)
    h5committest
---
 src/H5detect.c | 46 +++++++++++++++++++++++++++++-----------------
 1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/src/H5detect.c b/src/H5detect.c
index fb11322..eb8f9ac 100644
--- a/src/H5detect.c
+++ b/src/H5detect.c
@@ -112,14 +112,14 @@ precision (detected_t *d)
 	     */
 	    for (n=0; n<d->size && d->perm[n]<0; n++) /*void*/;
 	    d->precision = 8*(d->size-n);
-	    d->offset = 0;
+	    d->offset = 8*n;
 	} else if (d->perm[d->size - 1] < 0) {
 	    /*
 	     * Higher addresses are padded.
 	     */
 	    for (n=0; n<d->size && d->perm[d->size-(n+1)]; n++) /*void*/;
 	    d->precision = 8*(d->size-n);
-	    d->offset = 8*n;
+	    d->offset = 0;
 	} else {
 	    /*
 	     * No padding.
@@ -179,13 +179,13 @@ precision (detected_t *d)
       INFO.perm[_i] = _j;						      \
    }									      \
    INFO.sign = ('U'!=*(#VAR));						      \
-   ALIGNMENT(TYPE, INFO.align);						      \
+   precision (&(INFO));							      \
+   ALIGNMENT(TYPE, INFO);						      \
    if(!strcmp(INFO.varname, "SCHAR")  || !strcmp(INFO.varname, "SHORT") ||    \
       !strcmp(INFO.varname, "INT")   || !strcmp(INFO.varname, "LONG")  ||     \
       !strcmp(INFO.varname, "LLONG")) {                                       \
       COMP_ALIGNMENT(TYPE,INFO.comp_align);                                   \
    }                                                                          \
-   precision (&(INFO));							      \
 }
 
 /*-------------------------------------------------------------------------
@@ -267,12 +267,12 @@ precision (detected_t *d)
 									      \
    _v1 = 1.0;								      \
    INFO.bias = find_bias (INFO.epos, INFO.esize, INFO.perm, &_v1);	      \
-   ALIGNMENT(TYPE, INFO.align);						      \
+   precision (&(INFO));							      \
+   ALIGNMENT(TYPE, INFO);						      \
    if(!strcmp(INFO.varname, "FLOAT") || !strcmp(INFO.varname, "DOUBLE") ||    \
       !strcmp(INFO.varname, "LDOUBLE")) {                                     \
       COMP_ALIGNMENT(TYPE,INFO.comp_align);                                   \
    }                                                                          \
-   precision (&(INFO));							      \
 }
 
 
@@ -309,21 +309,33 @@ precision (detected_t *d)
 }
 
 #if defined(H5_HAVE_LONGJMP) && defined(H5_HAVE_SIGNAL)
-#define ALIGNMENT(TYPE,ALIGN) {						      \
+#define ALIGNMENT(TYPE,INFO) {						      \
     char		*volatile _buf=NULL;				      \
     volatile TYPE	_val=0;						      \
+    volatile TYPE	_val2;						      \
     volatile size_t	_ano=0;						      \
     void		(*_handler)(int) = signal(SIGBUS, sigbus_handler);    \
-    void		(*_handler2)(int) = signal(SIGSEGV, sigsegv_handler);    \
+    void		(*_handler2)(int) = signal(SIGSEGV, sigsegv_handler);	\
 									      \
     _buf = malloc(sizeof(TYPE)+align_g[NELMTS(align_g)-1]);		      \
     if (setjmp(jbuf_g)) _ano++;						      \
     if (_ano<NELMTS(align_g)) {						      \
-	*((TYPE*)(_buf+align_g[_ano])) = _val; /*possible SIGBUS or SEGSEGV*/	      \
-	_val = *((TYPE*)(_buf+align_g[_ano]));	/*possible SIGBUS or SEGSEGV*/	      \
-	(ALIGN)=align_g[_ano];						      \
+	*((TYPE*)(_buf+align_g[_ano])) = _val; /*possible SIGBUS or SEGSEGV*/	\
+	_val2 = *((TYPE*)(_buf+align_g[_ano]));	/*possible SIGBUS or SEGSEGV*/	\
+        /* Cray Check: This section helps detect alignment on Cray's */	      \
+        /*              vector machines (like the SV1) which mask off */      \
+        /*              pointer values when pointing to non-word aligned */   \
+        /*              locations with pointers that are supposed to be */    \
+        /*              word aligned. -QAK */                                 \
+        memset(_buf, 0xff, sizeof(TYPE)+align_g[NELMTS(align_g)-1]);	      \
+        memcpy(_buf+align_g[_ano]+(INFO.offset/8),((char *)&_val)+(INFO.offset/8),(INFO.precision/8)); \
+        _val2 = *((TYPE*)(_buf+align_g[_ano]));				      \
+	if(_val!=_val2)							      \
+	    longjmp(jbuf_g, 1);						      \
+        /* End Cray Check */						      \
+	(INFO.align)=align_g[_ano];					      \
     } else {								      \
-	(ALIGN)=0;							      \
+	(INFO.align)=0;							      \
 	fprintf(stderr, "unable to calculate alignment for %s\n", #TYPE);     \
     }									      \
     free(_buf);								      \
@@ -331,12 +343,12 @@ precision (detected_t *d)
     signal(SIGSEGV, _handler2); /*restore original handler*/		      \
 }
 #else
-#define ALIGNMENT(TYPE,ALIGN) (ALIGN)=0
+#define ALIGNMENT(TYPE,INFO) (INFO.align)=0
 #endif
 
 #if 0
 #if defined(H5_HAVE_FORK) && defined(H5_HAVE_WAITPID)
-#define ALIGNMENT(TYPE,ALIGN) {						      \
+#define ALIGNMENT(TYPE,INFO) {						      \
     char	*_buf;							      \
     TYPE	_val=0;							      \
     size_t	_ano;							      \
@@ -362,7 +374,7 @@ precision (detected_t *d)
 	    exit(1);							      \
 	}								      \
 	if (WIFEXITED(_status) && 0==WEXITSTATUS(_status)) {		      \
-	    ALIGN=align_g[_ano];					      \
+	    INFO.align=align_g[_ano];					      \
 	    break;							      \
 	}								      \
 	if (WIFSIGNALED(_status) && SIGBUS==WTERMSIG(_status)) {	      \
@@ -372,12 +384,12 @@ precision (detected_t *d)
 	break;								      \
     }									      \
     if (_ano>=NELMTS(align_g)) {					      \
-	ALIGN=0;							      \
+	INFO.align=0;							      \
 	fprintf(stderr, "unable to calculate alignment for %s\n", #TYPE);     \
     }									      \
 }
 #else
-#define ALIGNMENT(TYPE,ALIGN) (ALIGN)=0
+#define ALIGNMENT(TYPE,INFO) (INFO.align)=0
 #endif
 #endif
 
-- 
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