/* RTL-based forward propagation pass for GNU compiler.
- Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
Contributed by Paolo Bonzini and Steven Bosscher.
This file is part of GCC.
df_ref orig_use = use, new_use;
int width = -1;
int offset = -1;
- enum machine_mode mode = 0;
+ enum machine_mode mode = VOIDmode;
rtx *new_loc = find_occurrence (loc, DF_REF_REG (orig_use));
use_rec++;
return false;
}
+/* Try to replace USE with SRC (defined in DEF_INSN) in __asm. */
+
+static bool
+forward_propagate_asm (df_ref use, rtx def_insn, rtx def_set, rtx reg)
+{
+ rtx use_insn = DF_REF_INSN (use), src, use_pat, asm_operands, new_rtx, *loc;
+ int speed_p, i;
+ df_ref *use_vec;
+
+ gcc_assert ((DF_REF_FLAGS (use) & DF_REF_IN_NOTE) == 0);
+
+ src = SET_SRC (def_set);
+ use_pat = PATTERN (use_insn);
+
+ /* In __asm don't replace if src might need more registers than
+ reg, as that could increase register pressure on the __asm. */
+ use_vec = DF_INSN_USES (def_insn);
+ if (use_vec[0] && use_vec[1])
+ return false;
+
+ speed_p = optimize_bb_for_speed_p (BLOCK_FOR_INSN (use_insn));
+ asm_operands = NULL_RTX;
+ switch (GET_CODE (use_pat))
+ {
+ case ASM_OPERANDS:
+ asm_operands = use_pat;
+ break;
+ case SET:
+ if (MEM_P (SET_DEST (use_pat)))
+ {
+ loc = &SET_DEST (use_pat);
+ new_rtx = propagate_rtx (*loc, GET_MODE (*loc), reg, src, speed_p);
+ if (new_rtx)
+ validate_unshare_change (use_insn, loc, new_rtx, true);
+ }
+ asm_operands = SET_SRC (use_pat);
+ break;
+ case PARALLEL:
+ for (i = 0; i < XVECLEN (use_pat, 0); i++)
+ if (GET_CODE (XVECEXP (use_pat, 0, i)) == SET)
+ {
+ if (MEM_P (SET_DEST (XVECEXP (use_pat, 0, i))))
+ {
+ loc = &SET_DEST (XVECEXP (use_pat, 0, i));
+ new_rtx = propagate_rtx (*loc, GET_MODE (*loc), reg,
+ src, speed_p);
+ if (new_rtx)
+ validate_unshare_change (use_insn, loc, new_rtx, true);
+ }
+ asm_operands = SET_SRC (XVECEXP (use_pat, 0, i));
+ }
+ else if (GET_CODE (XVECEXP (use_pat, 0, i)) == ASM_OPERANDS)
+ asm_operands = XVECEXP (use_pat, 0, i);
+ break;
+ default:
+ gcc_unreachable ();
+ }
+
+ gcc_assert (asm_operands && GET_CODE (asm_operands) == ASM_OPERANDS);
+ for (i = 0; i < ASM_OPERANDS_INPUT_LENGTH (asm_operands); i++)
+ {
+ loc = &ASM_OPERANDS_INPUT (asm_operands, i);
+ new_rtx = propagate_rtx (*loc, GET_MODE (*loc), reg, src, speed_p);
+ if (new_rtx)
+ validate_unshare_change (use_insn, loc, new_rtx, true);
+ }
+
+ if (num_changes_pending () == 0 || !apply_change_group ())
+ return false;
+
+ num_changes++;
+ return true;
+}
+
/* Try to replace USE with SRC (defined in DEF_INSN) and simplify the
result. */
rtx src, reg, new_rtx, *loc;
bool set_reg_equal;
enum machine_mode mode;
+ int asm_use = -1;
+
+ if (INSN_CODE (use_insn) < 0)
+ asm_use = asm_noperands (PATTERN (use_insn));
- if (!use_set)
+ if (!use_set && asm_use < 0)
return false;
/* Do not propagate into PC, CC0, etc. */
- if (GET_MODE (SET_DEST (use_set)) == VOIDmode)
+ if (use_set && GET_MODE (SET_DEST (use_set)) == VOIDmode)
return false;
/* If def and use are subreg, check if they match. */
if (MEM_P (src) && MEM_READONLY_P (src))
{
rtx x = avoid_constant_pool_reference (src);
- if (x != src)
+ if (x != src && use_set)
{
rtx note = find_reg_note (use_insn, REG_EQUAL, NULL_RTX);
rtx old_rtx = note ? XEXP (note, 0) : SET_SRC (use_set);
return false;
}
+ if (asm_use >= 0)
+ return forward_propagate_asm (use, def_insn, def_set, reg);
+
/* Else try simplifying. */
if (DF_REF_TYPE (use) == DF_REF_REG_MEM_STORE)