diff options
Diffstat (limited to 'gcc/explow.c')
| -rw-r--r-- | gcc/explow.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/gcc/explow.c b/gcc/explow.c index 677ef7a..b56373c 100644 --- a/gcc/explow.c +++ b/gcc/explow.c @@ -39,6 +39,7 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA #include "recog.h" #include "langhooks.h" #include "target.h" +#include "output.h" static rtx break_out_memory_refs (rtx); static void emit_stack_probe (rtx); @@ -527,6 +528,7 @@ validize_mem (rtx ref) { if (!MEM_P (ref)) return ref; + ref = use_anchored_address (ref); if (! (flag_force_addr && CONSTANT_ADDRESS_P (XEXP (ref, 0))) && memory_address_p (GET_MODE (ref), XEXP (ref, 0))) return ref; @@ -534,6 +536,60 @@ validize_mem (rtx ref) /* Don't alter REF itself, since that is probably a stack slot. */ return replace_equiv_address (ref, XEXP (ref, 0)); } + +/* If X is a memory reference to a member of an object block, try rewriting + it to use an anchor instead. Return the new memory reference on success + and the old one on failure. */ + +rtx +use_anchored_address (rtx x) +{ + rtx base; + HOST_WIDE_INT offset; + + if (!flag_section_anchors) + return x; + + if (!MEM_P (x)) + return x; + + /* Split the address into a base and offset. */ + base = XEXP (x, 0); + offset = 0; + if (GET_CODE (base) == CONST + && GET_CODE (XEXP (base, 0)) == PLUS + && GET_CODE (XEXP (XEXP (base, 0), 1)) == CONST_INT) + { + offset += INTVAL (XEXP (XEXP (base, 0), 1)); + base = XEXP (XEXP (base, 0), 0); + } + + /* Check whether BASE is suitable for anchors. */ + if (GET_CODE (base) != SYMBOL_REF + || !SYMBOL_REF_IN_BLOCK_P (base) + || SYMBOL_REF_ANCHOR_P (base) + || !targetm.use_anchors_for_symbol_p (base)) + return x; + + /* Decide where BASE is going to be. */ + place_block_symbol (base); + + /* Get the anchor we need to use. */ + offset += SYMBOL_REF_BLOCK_OFFSET (base); + base = get_section_anchor (SYMBOL_REF_BLOCK (base), offset, + SYMBOL_REF_TLS_MODEL (base)); + + /* Work out the offset from the anchor. */ + offset -= SYMBOL_REF_BLOCK_OFFSET (base); + + /* If we're going to run a CSE pass, force the anchor into a register. + We will then be able to reuse registers for several accesses, if the + target costs say that that's worthwhile. */ + if (!cse_not_expected) + base = force_reg (GET_MODE (base), base); + + return replace_equiv_address (x, plus_constant (base, offset)); +} /* Copy the value or contents of X to a new temp reg and return that reg. */ |