diff options
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/config/aarch64/aarch64.c | 44 |
2 files changed, 49 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index ffef98259b9..70ef40f2f35 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2014-10-16 Richard Earnshaw <rearnsha@arm.com> + + * config/aarch64/aarch64.c (aarch64_legitimize_address): New function. + (TARGET_LEGITIMIZE_ADDRESS): Redefine. + 2014-10-16 Oleg Endo <olegendo@gcc.gnu.org> * config/sh/sh-protos.h (fldi_ok): Remove. diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c index db5ff59d92a..92c78543846 100644 --- a/gcc/config/aarch64/aarch64.c +++ b/gcc/config/aarch64/aarch64.c @@ -4167,6 +4167,47 @@ aarch64_regno_regclass (unsigned regno) return NO_REGS; } +static rtx +aarch64_legitimize_address (rtx x, rtx /* orig_x */, enum machine_mode mode) +{ + /* Try to split X+CONST into Y=X+(CONST & ~mask), Y+(CONST&mask), + where mask is selected by alignment and size of the offset. + We try to pick as large a range for the offset as possible to + maximize the chance of a CSE. However, for aligned addresses + we limit the range to 4k so that structures with different sized + elements are likely to use the same base. */ + + if (GET_CODE (x) == PLUS && CONST_INT_P (XEXP (x, 1))) + { + HOST_WIDE_INT offset = INTVAL (XEXP (x, 1)); + HOST_WIDE_INT base_offset; + + /* Does it look like we'll need a load/store-pair operation? */ + if (GET_MODE_SIZE (mode) > 16 + || mode == TImode) + base_offset = ((offset + 64 * GET_MODE_SIZE (mode)) + & ~((128 * GET_MODE_SIZE (mode)) - 1)); + /* For offsets aren't a multiple of the access size, the limit is + -256...255. */ + else if (offset & (GET_MODE_SIZE (mode) - 1)) + base_offset = (offset + 0x100) & ~0x1ff; + else + base_offset = offset & ~0xfff; + + if (base_offset == 0) + return x; + + offset -= base_offset; + rtx base_reg = gen_reg_rtx (Pmode); + rtx val = force_operand (plus_constant (Pmode, XEXP (x, 0), base_offset), + NULL_RTX); + emit_move_insn (base_reg, val); + x = plus_constant (Pmode, base_reg, offset); + } + + return x; +} + /* Try a machine-dependent way of reloading an illegitimate address operand. If we find one, push the reload and return the new rtx. */ @@ -10165,6 +10206,9 @@ aarch64_asan_shadow_offset (void) #undef TARGET_ASAN_SHADOW_OFFSET #define TARGET_ASAN_SHADOW_OFFSET aarch64_asan_shadow_offset +#undef TARGET_LEGITIMIZE_ADDRESS +#define TARGET_LEGITIMIZE_ADDRESS aarch64_legitimize_address + struct gcc_target targetm = TARGET_INITIALIZER; #include "gt-aarch64.h" |