diff options
Diffstat (limited to 'gcc/tree-vect-patterns.c')
| -rw-r--r-- | gcc/tree-vect-patterns.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/gcc/tree-vect-patterns.c b/gcc/tree-vect-patterns.c index 8997340..e6c5bcd 100644 --- a/gcc/tree-vect-patterns.c +++ b/gcc/tree-vect-patterns.c @@ -1268,11 +1268,31 @@ vect_recog_widen_op_pattern (vec_info *vinfo, /* Check target support */ tree vectype = get_vectype_for_scalar_type (vinfo, half_type); tree vecitype = get_vectype_for_scalar_type (vinfo, itype); + tree ctype = itype; + tree vecctype = vecitype; + if (orig_code == MINUS_EXPR + && TYPE_UNSIGNED (itype) + && TYPE_PRECISION (type) > TYPE_PRECISION (itype)) + { + /* Subtraction is special, even if half_type is unsigned and no matter + whether type is signed or unsigned, if type is wider than itype, + we need to sign-extend from the widening operation result to the + result type. + Consider half_type unsigned char, operand 1 0xfe, operand 2 0xff, + itype unsigned short and type either int or unsigned int. + Widened (unsigned short) 0xfe - (unsigned short) 0xff is + (unsigned short) 0xffff, but for type int we want the result -1 + and for type unsigned int 0xffffffff rather than 0xffff. */ + ctype = build_nonstandard_integer_type (TYPE_PRECISION (itype), 0); + vecctype = get_vectype_for_scalar_type (vinfo, ctype); + } + enum tree_code dummy_code; int dummy_int; auto_vec<tree> dummy_vec; if (!vectype || !vecitype + || !vecctype || !supportable_widening_operation (vinfo, wide_code, last_stmt_info, vecitype, vectype, &dummy_code, &dummy_code, @@ -1291,8 +1311,12 @@ vect_recog_widen_op_pattern (vec_info *vinfo, gimple *pattern_stmt = gimple_build_assign (var, wide_code, oprnd[0], oprnd[1]); + if (vecctype != vecitype) + pattern_stmt = vect_convert_output (vinfo, last_stmt_info, ctype, + pattern_stmt, vecitype); + return vect_convert_output (vinfo, last_stmt_info, - type, pattern_stmt, vecitype); + type, pattern_stmt, vecctype); } /* Try to detect multiplication on widened inputs, converting MULT_EXPR |