diff options
| -rwxr-xr-x | Configure | 85 | ||||
| -rw-r--r-- | Cross/config.sh-arm-linux | 1 | ||||
| -rw-r--r-- | NetWare/config.wc | 1 | ||||
| -rw-r--r-- | Porting/Glossary | 5 | ||||
| -rw-r--r-- | Porting/config.sh | 1 | ||||
| -rw-r--r-- | Porting/config_H | 7 | ||||
| -rw-r--r-- | config_h.SH | 7 | ||||
| -rw-r--r-- | configure.com | 2 | ||||
| -rw-r--r-- | epoc/config.sh | 1 | ||||
| -rw-r--r-- | plan9/config_sh.sample | 1 | ||||
| -rw-r--r-- | sv.c | 12 | ||||
| -rw-r--r-- | symbian/config.sh | 1 | ||||
| -rwxr-xr-x | t/op/inc.t | 29 | ||||
| -rwxr-xr-x | uconfig.sh | 1 | ||||
| -rw-r--r-- | win32/config.bc | 1 | ||||
| -rw-r--r-- | win32/config.ce | 1 | ||||
| -rw-r--r-- | win32/config.gc | 1 | ||||
| -rw-r--r-- | win32/config.vc | 1 | ||||
| -rw-r--r-- | win32/config.vc64 | 1 |
19 files changed, 144 insertions, 15 deletions
@@ -1058,6 +1058,7 @@ i8type='' ivsize='' ivtype='' nv_preserves_uv_bits='' +nv_overflows_integers_at='' nvsize='' nvtype='' u16size='' @@ -15468,6 +15469,89 @@ case "$nv_preserves_uv_bits" in esac $rm_try +$echo "Checking to find the largest integer value your NVs can hold..." >&4 +: volatile so that the compiler has to store it out to memory. +if test X"$d_volatile" = X"$define"; then + volatile=volatile +fi +$cat <<EOP >try.c +#include <stdio.h> + +typedef $nvtype NV; + +int +main() { + NV value = 2; + int count = 1; + + while(count < 256) { + $volatile NV up = value + 1.0; + $volatile NV negated = -value; + $volatile NV down = negated - 1.0; + $volatile NV got_up = up - value; + int up_good = got_up == 1.0; + int got_down = down - negated; + int down_good = got_down == -1.0; + + if (down_good != up_good) { + fprintf(stderr, + "Inconsistency - up %d %f; down %d %f; for 2**%d (%.20f)\n", + up_good, (double) got_up, down_good, (double) got_down, + count, (double) value); + return 1; + } + if (!up_good) { + while (1) { + if (count > 8) { + count -= 8; + fputs("256.0", stdout); + } else { + count--; + fputs("2.0", stdout); + } + if (!count) { + puts(""); + return 0; + } + fputs("*", stdout); + } + } + value *= 2; + ++count; + } + fprintf(stderr, "Cannot overflow integer range, even at 2**%d (%.20f)\n", + count, (double) value); + return 1; +} +EOP +set try + +nv_overflows_integers_at='0' +if eval $compile; then + xxx="`$run ./try`" + case "$?" in + 0) + case "$xxx" in + 2*) cat >&4 <<EOM +The largest integer your NVs can preserve is equal to $xxx +EOM + nv_overflows_integers_at="$xxx" + ;; + *) cat >&4 <<EOM +Cannot determine the largest integer value your NVs can hold, unexpected output +'$xxx' +EOM + ;; + esac + ;; + *) cat >&4 <<EOM +Cannot determine the largest integer value your NVs can hold +EOM + ;; + esac +fi +$rm_try + $echo "Checking whether NV 0.0 is all bits zero in memory..." >&4 : volatile so that the compiler has to store it out to memory. if test X"$d_volatile" = X"$define"; then @@ -22420,6 +22504,7 @@ nroff='$nroff' nvEUformat='$nvEUformat' nvFUformat='$nvFUformat' nvGUformat='$nvGUformat' +nv_overflows_integers_at='$nv_overflows_integers_at' nv_preserves_uv_bits='$nv_preserves_uv_bits' nveformat='$nveformat' nvfformat='$nvfformat' diff --git a/Cross/config.sh-arm-linux b/Cross/config.sh-arm-linux index ec468909a8..ee44d1180c 100644 --- a/Cross/config.sh-arm-linux +++ b/Cross/config.sh-arm-linux @@ -808,6 +808,7 @@ nvEUformat='"E"' nvFUformat='"F"' nvGUformat='"G"' nv_preserves_uv_bits='32' +nv_overflows_integers_at='256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0' nveformat='"e"' nvfformat='"f"' nvgformat='"g"' diff --git a/NetWare/config.wc b/NetWare/config.wc index 942226c899..092a821eba 100644 --- a/NetWare/config.wc +++ b/NetWare/config.wc @@ -784,6 +784,7 @@ nvEUformat='"E"' nvFUformat='"F"' nvGUformat='"G"' nv_preserves_uv_bits='32' +nv_overflows_integers_at='256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0' nveformat='"e"' nvfformat='"f"' nvgformat='"g"' diff --git a/Porting/Glossary b/Porting/Glossary index a457ed5b32..42d75a14ef 100644 --- a/Porting/Glossary +++ b/Porting/Glossary @@ -3799,6 +3799,11 @@ nv_preserves_uv_bits (perlxv.U): This variable indicates how many of bits type uvtype a variable nvtype can preserve. +nv_overflows_integers_at (perlxv.U): + This variable gives the largest integer value that NVs can hold + as a constant floating point expression. + If it could not be determined, it holds the value 0. + nveformat (perlxvf.U): This variable contains the format string used for printing a Perl NV using %e-ish floating point format. diff --git a/Porting/config.sh b/Porting/config.sh index b20a656f6f..eb9ab0192a 100644 --- a/Porting/config.sh +++ b/Porting/config.sh @@ -824,6 +824,7 @@ nroff='nroff' nvEUformat='"E"' nvFUformat='"F"' nvGUformat='"G"' +nv_overflows_integers_at='256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0' nv_preserves_uv_bits='53' nveformat='"e"' nvfformat='"f"' diff --git a/Porting/config_H b/Porting/config_H index 2540a14d8e..f74dc6714d 100644 --- a/Porting/config_H +++ b/Porting/config_H @@ -4271,6 +4271,12 @@ * This symbol contains the number of bits a variable of type NVTYPE * can preserve of a variable of type UVTYPE. */ +/* NV_OVERFLOWS_INTEGERS_AT + * This symbol gives the largest integer value that NVs can hold. This + * value + 1.0 cannot be stored accurately. It is expressed as constant + * floating point expression to reduce the chance of decimale/binary + * conversion issues. If it can not be determined, the value 0 is given. + */ /* NV_ZERO_IS_ALLBITS_ZERO: * This symbol, if defined, indicates that a variable of type NVTYPE * stores 0.0 in memory as all bits zero. @@ -4303,6 +4309,7 @@ #define NVSIZE 8 /**/ #undef NV_PRESERVES_UV #define NV_PRESERVES_UV_BITS 53 +#define NV_OVERFLOWS_INTEGERS_AT 256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0 #define NV_ZERO_IS_ALLBITS_ZERO #if UVSIZE == 8 # ifdef BYTEORDER diff --git a/config_h.SH b/config_h.SH index 16160e5e07..47604e9660 100644 --- a/config_h.SH +++ b/config_h.SH @@ -4300,6 +4300,12 @@ sed <<!GROK!THIS! >$CONFIG_H -e 's!^#undef\(.*/\)\*!/\*#define\1 \*!' -e 's!^#un * This symbol contains the number of bits a variable of type NVTYPE * can preserve of a variable of type UVTYPE. */ +/* NV_OVERFLOWS_INTEGERS_AT + * This symbol gives the largest integer value that NVs can hold. This + * value + 1.0 cannot be stored accurately. It is expressed as constant + * floating point expression to reduce the chance of decimale/binary + * conversion issues. If it can not be determined, the value 0 is given. + */ /* NV_ZERO_IS_ALLBITS_ZERO: * This symbol, if defined, indicates that a variable of type NVTYPE * stores 0.0 in memory as all bits zero. @@ -4332,6 +4338,7 @@ sed <<!GROK!THIS! >$CONFIG_H -e 's!^#undef\(.*/\)\*!/\*#define\1 \*!' -e 's!^#un #define NVSIZE $nvsize /**/ #$d_nv_preserves_uv NV_PRESERVES_UV #define NV_PRESERVES_UV_BITS $nv_preserves_uv_bits +#define NV_OVERFLOWS_INTEGERS_AT $nv_overflows_integers_at #$d_nv_zero_is_allbits_zero NV_ZERO_IS_ALLBITS_ZERO #if UVSIZE == 8 # ifdef BYTEORDER diff --git a/configure.com b/configure.com index ee0f1cce53..501ade35e4 100644 --- a/configure.com +++ b/configure.com @@ -5939,6 +5939,8 @@ $ WC "d_nanosleep='" + d_nanosleep + "'" $ WC "d_nice='define'" $ WC "d_nl_langinfo='" + d_nl_langinfo + "'" $ WC "d_nv_preserves_uv='" + d_nv_preserves_uv + "'" +$! Pending integrating the probe test +$ WC "nv_overflows_integers_at='0'" $ WC "nv_preserves_uv_bits='" + nv_preserves_uv_bits + "'" $ WC "d_nv_zero_is_allbits_zero='define'" $ WC "d_off64_t='" + d_off64_t + "'" diff --git a/epoc/config.sh b/epoc/config.sh index bd1a20fab3..75d4260091 100644 --- a/epoc/config.sh +++ b/epoc/config.sh @@ -970,6 +970,7 @@ d_strtoll='undef' d_strtouq='undef' d_nv_preserves_uv='define' nv_preserves_uv_bits='32' +nv_overflows_integers_at='0' useithreads='undef' inc_version_list=' ' inc_version_list_init='0' diff --git a/plan9/config_sh.sample b/plan9/config_sh.sample index 9ce1038812..8907af79f9 100644 --- a/plan9/config_sh.sample +++ b/plan9/config_sh.sample @@ -789,6 +789,7 @@ nvEUformat='"E"' nvFUformat='"F"' nvGUformat='"G"' nv_preserves_uv_bits='31' +nv_overflows_integers_at='256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0' nveformat='"e"' nvfformat='"f"' nvgformat='"g"' @@ -6802,14 +6802,14 @@ Perl_sv_inc(pTHX_ register SV *sv) } if (flags & SVp_NOK) { const NV was = SvNVX(sv); - const NV now = was + 1.0; - if (now - was != 1.0 && ckWARN(WARN_IMPRECISION)) { + if (NV_OVERFLOWS_INTEGERS_AT && + was >= NV_OVERFLOWS_INTEGERS_AT && ckWARN(WARN_IMPRECISION)) { Perl_warner(aTHX_ packWARN(WARN_IMPRECISION), "Lost precision when incrementing %" NVff " by 1", was); } (void)SvNOK_only(sv); - SvNV_set(sv, now); + SvNV_set(sv, was + 1.0); return; } @@ -6968,14 +6968,14 @@ Perl_sv_dec(pTHX_ register SV *sv) oops_its_num: { const NV was = SvNVX(sv); - const NV now = was - 1.0; - if (now - was != -1.0 && ckWARN(WARN_IMPRECISION)) { + if (NV_OVERFLOWS_INTEGERS_AT && + was <= -NV_OVERFLOWS_INTEGERS_AT && ckWARN(WARN_IMPRECISION)) { Perl_warner(aTHX_ packWARN(WARN_IMPRECISION), "Lost precision when decrementing %" NVff " by 1", was); } (void)SvNOK_only(sv); - SvNV_set(sv, now); + SvNV_set(sv, was - 1.0); return; } } diff --git a/symbian/config.sh b/symbian/config.sh index e53ed934e7..59925bf9cb 100644 --- a/symbian/config.sh +++ b/symbian/config.sh @@ -661,6 +661,7 @@ nv_preserves_uv_bits='0' nveformat='"e"' nvfformat='"f"' nvgformat='"g"' +nv_overflows_integers_at='256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0' nvsize='8' nvtype='double' o_nonblock='O_NONBLOCK' diff --git a/t/op/inc.t b/t/op/inc.t index 95b0698734..f722336d5b 100755 --- a/t/op/inc.t +++ b/t/op/inc.t @@ -233,25 +233,36 @@ EOC } } +my $h_uv_max = 1 + (~0 >> 1); my $found; for my $n (47..113) { my $power_of_2 = 2**$n; my $plus_1 = $power_of_2 + 1; next if $plus_1 != $power_of_2; - print "# Testing for 2**$n ($power_of_2) which overflows the mantissa\n"; - # doing int here means that for NV > IV on the first go we're in the - # IV upgrade to NV case, and the second go we're in the NV already case. - my $start = int($power_of_2 - 2); - my $check = $power_of_2 - 2; - die "Something wrong with our rounding assumptions: $check vs $start" - unless $start == $check; + my ($start_p, $start_n); + if ($h_uv_max > $power_of_2 / 2) { + my $uv_max = 1 + 2 * (~0 >> 1); + # UV_MAX is 2**$something - 1, so subtract 1 to get the start value + $start_p = $uv_max - 1; + # whereas IV_MIN is -(2**$something), so subtract 2 + $start_n = -$h_uv_max + 2; + print "# Mantissa overflows at 2**$n ($power_of_2)\n"; + print "# But max UV ($uv_max) is greater so testing that\n"; + } else { + print "# Testing 2**$n ($power_of_2) which overflows the mantissa\n"; + $start_p = int($power_of_2 - 2); + $start_n = -$start_p; + my $check = $power_of_2 - 2; + die "Something wrong with our rounding assumptions: $check vs $start_p" + unless $start_p == $check; + } foreach my $warn (0, 1) { foreach (['++$i', 'pre-inc'], ['$i++', 'post-inc']) { - check_some_code($start, $warn, @$_); + check_some_code($start_p, $warn, @$_); } foreach (['--$i', 'pre-dec'], ['$i--', 'post-dec']) { - check_some_code(-$start, $warn, @$_); + check_some_code($start_n, $warn, @$_); } } diff --git a/uconfig.sh b/uconfig.sh index 4fa6a0ac52..3f9813c701 100755 --- a/uconfig.sh +++ b/uconfig.sh @@ -269,6 +269,7 @@ d_nl_langinfo='undef' d_nv_preserves_uv='undef' d_nv_zero_is_allbits_zero='undef' nv_preserves_uv_bits='0' +nv_overflows_integers_at='256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0' d_off64_t='undef' d_old_pthread_create_joinable='undef' d_oldpthreads='undef' diff --git a/win32/config.bc b/win32/config.bc index ec883a98d7..a2aa97953c 100644 --- a/win32/config.bc +++ b/win32/config.bc @@ -802,6 +802,7 @@ nvEUformat='"E"' nvFUformat='"F"' nvGUformat='"G"' nv_preserves_uv_bits='32' +nv_overflows_integers_at='256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0' nveformat='"e"' nvfformat='"f"' nvgformat='"g"' diff --git a/win32/config.ce b/win32/config.ce index 00dabcfe0b..b722e6a141 100644 --- a/win32/config.ce +++ b/win32/config.ce @@ -775,6 +775,7 @@ nm_so_opt='' nonxs_ext='Errno' nroff='' nv_preserves_uv_bits='32' +nv_overflows_integers_at='256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0' nveformat='"e"' nvfformat='"f"' nvgformat='"g"' diff --git a/win32/config.gc b/win32/config.gc index 5e6267886f..4c932cddf1 100644 --- a/win32/config.gc +++ b/win32/config.gc @@ -802,6 +802,7 @@ nvEUformat='"E"' nvFUformat='"F"' nvGUformat='"G"' nv_preserves_uv_bits='32' +nv_overflows_integers_at='256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0' nveformat='"e"' nvfformat='"f"' nvgformat='"g"' diff --git a/win32/config.vc b/win32/config.vc index 3c58cdcf34..3f9be6d2d4 100644 --- a/win32/config.vc +++ b/win32/config.vc @@ -802,6 +802,7 @@ nvEUformat='"E"' nvFUformat='"F"' nvGUformat='"G"' nv_preserves_uv_bits='32' +nv_overflows_integers_at='256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0' nveformat='"e"' nvfformat='"f"' nvgformat='"g"' diff --git a/win32/config.vc64 b/win32/config.vc64 index 6680911655..c88143946e 100644 --- a/win32/config.vc64 +++ b/win32/config.vc64 @@ -802,6 +802,7 @@ nvEUformat='"E"' nvFUformat='"F"' nvGUformat='"G"' nv_preserves_uv_bits='53' +nv_overflows_integers_at='256.0*256.0*256.0*256.0*256.0*256.0*2.0*2.0*2.0*2.0*2.0' nveformat='"e"' nvfformat='"f"' nvgformat='"g"' |