Richard Henderson wrote:
While the first set of changes looks good to me, I don't understand those: > @@ -4728,7 +4733,12 @@ init_alignment_context (struct alignment_context *ac, > rtx mem, > ac->aligned = (MEM_ALIGN (mem) >= GET_MODE_BITSIZE (SImode)); > > if (ac->aligned) > - ac->memsi = adjust_address (mem, SImode, 0); /* Memory is aligned. */ > + { > + ac->memsi = adjust_address (mem, SImode, 0); /* Memory is aligned. */ > + ac->shift = const0_rtx; > + ac->modemask = GEN_INT (GET_MODE_MASK (mode)); > + ac->modemaski = GEN_INT (~GET_MODE_MASK (mode)); > + } > else > { > /* Alignment is unknown. */ > @@ -4755,15 +4765,17 @@ init_alignment_context (struct alignment_context *ac, > rtx mem, > ac->shift = expand_simple_binop (SImode, MINUS, ac->shift, byteoffset, > NULL_RTX, 1, OPTAB_DIRECT); > > + /* Shift is the byte count, but we need the bitcount. */ > + ac->shift = expand_simple_binop (SImode, ASHIFT, ac->shift, GEN_INT > (3), > + NULL_RTX, 1, OPTAB_DIRECT); > + > + /* Calculate masks. */ > + ac->modemask = expand_simple_binop (SImode, ASHIFT, > + GEN_INT (GET_MODE_MASK (mode)), > + ac->shift, NULL_RTX, 1, OPTAB_DIRECT); > + ac->modemaski = expand_simple_unop (SImode, NOT, ac->modemask, > + NULL_RTX, 1); > } > - /* Shift is the byte count, but we need the bitcount. */ > - ac->shift = expand_simple_binop (SImode, MULT, ac->shift, GEN_INT > (BITS_PER_UNIT), > - NULL_RTX, 1, OPTAB_DIRECT); > - /* Calculate masks. */ > - ac->modemask = expand_simple_binop (SImode, ASHIFT, > - GEN_INT (GET_MODE_MASK (mode)), ac->shift, > - NULL_RTX, 1, OPTAB_DIRECT); > - ac->modemaski = expand_simple_unop (SImode, NOT, ac->modemask, NULL_RTX, > 1); > } > > /* A subroutine of s390_expand_cs_hqi. Insert INS into VAL. If possible, > @@ -4781,7 +4793,7 @@ s390_two_part_insv (struct alignment_context *ac, rtx > *seq1, rtx *seq2, > start_sequence (); > tmp = copy_to_mode_reg (SImode, val); > if (s390_expand_insv (tmp, GEN_INT (GET_MODE_BITSIZE (mode)), > - const0_rtx, ins)) > + GEN_INT (32 - GET_MODE_BITSIZE (mode)), ins)) > { > *seq1 = NULL; > *seq2 = get_insns (); "aligned" accesses do involve the *most significant* part of the word (on a big-endian machine), which means ac->shift has to be set to modesize (outer) - modesize (inner), and expand_insv needs to be called with bitpos 0 (due to bits-big-endian). When reverting this part of your patch (and together with the EQ/NE fix pointed out here: http://gcc.gnu.org/ml/gcc-patches/2012-08/msg00170.html), I can complete a bootstrap/testing cycle without regressions. (There's still code being generated that looks a bit inefficient, but that's a different story.) Bye, Ulrich -- Dr. Ulrich Weigand GNU Toolchain for Linux on System z and Cell BE ulrich.weig...@de.ibm.com