| Message ID | 87zjj0ng27.fsf@sandifor-thinkpad.stglab.manchester.uk.ibm.com |
|---|---|
| State | New |
| Headers | show |
These are fine. On 05/02/2014 03:20 PM, Richard Sandiford wrote: > This patch adds some assertions against sext (.., 0) and zext (..., 0). > The former is undefined at the sext_hwi level and the latter is disallowed > for consistency with the former. > > Also, set_bit (rightly IMO) can't handle bit >= precision. For > precision <= HOST_BITS_PER_WIDE_INT it would invoke undefined > behaviour while for other precisions I think it would crash. > A case with precision <= HOST_BITS_PER_WIDE_INT showed up in java > (fix posted separately). > > Tested on x86_64-linux-gnu and powerpc64-linux-gnu. OK to install? > > Thanks, > Richard > > > Index: gcc/wide-int.h > =================================================================== > --- gcc/wide-int.h 2014-05-02 16:28:09.561842842 +0100 > +++ gcc/wide-int.h 2014-05-02 16:44:04.015463718 +0100 > @@ -2046,6 +2046,8 @@ wi::sext (const T &x, unsigned int offse > unsigned int precision = get_precision (result); > WIDE_INT_REF_FOR (T) xi (x, precision); > > + gcc_checking_assert (offset != 0); > + > if (offset <= HOST_BITS_PER_WIDE_INT) > { > val[0] = sext_hwi (xi.ulow (), offset); > @@ -2065,6 +2067,8 @@ wi::zext (const T &x, unsigned int offse > unsigned int precision = get_precision (result); > WIDE_INT_REF_FOR (T) xi (x, precision); > > + gcc_checking_assert (offset != 0); > + > /* This is not just an optimization, it is actually required to > maintain canonization. */ > if (offset >= precision) > @@ -2102,6 +2106,9 @@ wi::set_bit (const T &x, unsigned int bi > WI_UNARY_RESULT_VAR (result, val, T, x); > unsigned int precision = get_precision (result); > WIDE_INT_REF_FOR (T) xi (x, precision); > + > + gcc_checking_assert (bit < precision); > + > if (precision <= HOST_BITS_PER_WIDE_INT) > { > val[0] = xi.ulow () | ((unsigned HOST_WIDE_INT) 1 << bit);
Kenneth Zadeck <zadeck@naturalbridge.com> writes: > These are fine. Thanks. I'll hold off applying it until the java fix has been reviewed (which could be after the merge -- no need to hold it up for this IMO). Richard > > On 05/02/2014 03:20 PM, Richard Sandiford wrote: >> This patch adds some assertions against sext (.., 0) and zext (..., 0). >> The former is undefined at the sext_hwi level and the latter is disallowed >> for consistency with the former. >> >> Also, set_bit (rightly IMO) can't handle bit >= precision. For >> precision <= HOST_BITS_PER_WIDE_INT it would invoke undefined >> behaviour while for other precisions I think it would crash. >> A case with precision <= HOST_BITS_PER_WIDE_INT showed up in java >> (fix posted separately). >> >> Tested on x86_64-linux-gnu and powerpc64-linux-gnu. OK to install? >> >> Thanks, >> Richard >> >> >> Index: gcc/wide-int.h >> =================================================================== >> --- gcc/wide-int.h 2014-05-02 16:28:09.561842842 +0100 >> +++ gcc/wide-int.h 2014-05-02 16:44:04.015463718 +0100 >> @@ -2046,6 +2046,8 @@ wi::sext (const T &x, unsigned int offse >> unsigned int precision = get_precision (result); >> WIDE_INT_REF_FOR (T) xi (x, precision); >> >> + gcc_checking_assert (offset != 0); >> + >> if (offset <= HOST_BITS_PER_WIDE_INT) >> { >> val[0] = sext_hwi (xi.ulow (), offset); >> @@ -2065,6 +2067,8 @@ wi::zext (const T &x, unsigned int offse >> unsigned int precision = get_precision (result); >> WIDE_INT_REF_FOR (T) xi (x, precision); >> >> + gcc_checking_assert (offset != 0); >> + >> /* This is not just an optimization, it is actually required to >> maintain canonization. */ >> if (offset >= precision) >> @@ -2102,6 +2106,9 @@ wi::set_bit (const T &x, unsigned int bi >> WI_UNARY_RESULT_VAR (result, val, T, x); >> unsigned int precision = get_precision (result); >> WIDE_INT_REF_FOR (T) xi (x, precision); >> + >> + gcc_checking_assert (bit < precision); >> + >> if (precision <= HOST_BITS_PER_WIDE_INT) >> { >> val[0] = xi.ulow () | ((unsigned HOST_WIDE_INT) 1 << bit);
Index: gcc/wide-int.h =================================================================== --- gcc/wide-int.h 2014-05-02 16:28:09.561842842 +0100 +++ gcc/wide-int.h 2014-05-02 16:44:04.015463718 +0100 @@ -2046,6 +2046,8 @@ wi::sext (const T &x, unsigned int offse unsigned int precision = get_precision (result); WIDE_INT_REF_FOR (T) xi (x, precision); + gcc_checking_assert (offset != 0); + if (offset <= HOST_BITS_PER_WIDE_INT) { val[0] = sext_hwi (xi.ulow (), offset); @@ -2065,6 +2067,8 @@ wi::zext (const T &x, unsigned int offse unsigned int precision = get_precision (result); WIDE_INT_REF_FOR (T) xi (x, precision); + gcc_checking_assert (offset != 0); + /* This is not just an optimization, it is actually required to maintain canonization. */ if (offset >= precision) @@ -2102,6 +2106,9 @@ wi::set_bit (const T &x, unsigned int bi WI_UNARY_RESULT_VAR (result, val, T, x); unsigned int precision = get_precision (result); WIDE_INT_REF_FOR (T) xi (x, precision); + + gcc_checking_assert (bit < precision); + if (precision <= HOST_BITS_PER_WIDE_INT) { val[0] = xi.ulow () | ((unsigned HOST_WIDE_INT) 1 << bit);