backport: re PR middle-end/36578 (cast to long double not taken into account when...

backport: re PR middle-end/36578 (cast to long double not taken into account when result stored to a double)

2009-02-25  Janis Johnson  <janis187@us.ibm.com>

gcc/
	Backport from mainline:
	2008-10-29  Joseph Myers  <joseph@codesourcery.com>

	PR middle-end/36578
	* convert.c (convert_to_real): Do not optimize conversions of
	binary arithmetic operations between binary and decimal
	floating-point types.  Consider mode of target type in determining
	decimal type for arithmetic.  Unless
	flag_unsafe_math_optimizations, do not optimize binary conversions
	where this may change rounding behavior.
	* real.c (real_can_shorten_arithmetic): New.
	* real.h (real_can_shorten_arithmetic): Declare.

gcc/testsuite/
	Backport from mainline:
	2008-10-29  Joseph Myers  <joseph@codesourcery.com>

	PR middle-end/36578
	* gcc.dg/dfp/convert-bfp-13.c, gcc.dg/dfp/convert-bfp-14.c,
	gcc.dg/dfp/convert-dfp-fold-2.c, gcc.target/i386/pr36578-1.c,
	gcc.target/i386/pr36578-2.c: New tests.

From-SVN: r144436