diff options
Diffstat (limited to 'gcc/emit-rtl.c')
| -rw-r--r-- | gcc/emit-rtl.c | 51 |
1 files changed, 33 insertions, 18 deletions
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c index da4f533..ac6fd6a 100644 --- a/gcc/emit-rtl.c +++ b/gcc/emit-rtl.c @@ -816,6 +816,8 @@ validate_subreg (machine_mode omode, machine_mode imode, if (offset >= isize) return false; + unsigned int regsize = REGMODE_NATURAL_SIZE (imode); + /* ??? This should not be here. Temporarily continue to allow word_mode subregs of anything. The most common offender is (subreg:SI (reg:DF)). Generally, backends are doing something sketchy but it'll take time to @@ -824,7 +826,7 @@ validate_subreg (machine_mode omode, machine_mode imode, ; /* ??? Similarly, e.g. with (subreg:DF (reg:TI)). Though store_bit_field is the culprit here, and not the backends. */ - else if (osize >= UNITS_PER_WORD && isize >= osize) + else if (osize >= regsize && isize >= osize) ; /* Allow component subregs of complex and vector. Though given the below extraction rules, it's not always clear what that means. */ @@ -876,17 +878,23 @@ validate_subreg (machine_mode omode, machine_mode imode, } /* For pseudo registers, we want most of the same checks. Namely: - If the register no larger than a word, the subreg must be lowpart. - If the register is larger than a word, the subreg must be the lowpart - of a subword. A subreg does *not* perform arbitrary bit extraction. - Given that we've already checked mode/offset alignment, we only have - to check subword subregs here. */ - if (osize < UNITS_PER_WORD + + Assume that the pseudo register will be allocated to hard registers + that can hold REGSIZE bytes each. If OSIZE is not a multiple of REGSIZE, + the remainder must correspond to the lowpart of the containing hard + register. If BYTES_BIG_ENDIAN, the lowpart is at the highest offset, + otherwise it is at the lowest offset. + + Given that we've already checked the mode and offset alignment, + we only have to check subblock subregs here. */ + if (osize < regsize && ! (lra_in_progress && (FLOAT_MODE_P (imode) || FLOAT_MODE_P (omode)))) { - machine_mode wmode = isize > UNITS_PER_WORD ? word_mode : imode; - unsigned int low_off = subreg_lowpart_offset (omode, wmode); - if (offset % UNITS_PER_WORD != low_off) + unsigned int block_size = MIN (isize, regsize); + unsigned int offset_within_block = offset % block_size; + if (BYTES_BIG_ENDIAN + ? offset_within_block != block_size - osize + : offset_within_block != 0) return false; } return true; @@ -1439,14 +1447,21 @@ gen_lowpart_common (machine_mode mode, rtx x) if (innermode == mode) return x; - /* MODE must occupy no more words than the mode of X. */ - if ((msize + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD - > ((xsize + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)) - return 0; - - /* Don't allow generating paradoxical FLOAT_MODE subregs. */ - if (SCALAR_FLOAT_MODE_P (mode) && msize > xsize) - return 0; + if (SCALAR_FLOAT_MODE_P (mode)) + { + /* Don't allow paradoxical FLOAT_MODE subregs. */ + if (msize > xsize) + return 0; + } + else + { + /* MODE must occupy no more of the underlying registers than X. */ + unsigned int regsize = REGMODE_NATURAL_SIZE (innermode); + unsigned int mregs = CEIL (msize, regsize); + unsigned int xregs = CEIL (xsize, regsize); + if (mregs > xregs) + return 0; + } scalar_int_mode int_mode, int_innermode, from_mode; if ((GET_CODE (x) == ZERO_EXTEND || GET_CODE (x) == SIGN_EXTEND) |