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| author | Richard Kenner <kenner@gcc.gnu.org> | 1994-05-17 15:51:48 -0400 |
|---|---|---|
| committer | Richard Kenner <kenner@gcc.gnu.org> | 1994-05-17 15:51:48 -0400 |
| commit | 9d926da5630b8a633a1d25d604f3fb6c9e0271f7 (patch) | |
| tree | 131f1a968a221c3f3c402905c548821db1f52d53 /gcc/reload.c | |
| parent | a533969946ef38da61a5264d06faba0aedfed216 (diff) | |
| download | gcc-9d926da5630b8a633a1d25d604f3fb6c9e0271f7.zip gcc-9d926da5630b8a633a1d25d604f3fb6c9e0271f7.tar.gz gcc-9d926da5630b8a633a1d25d604f3fb6c9e0271f7.tar.bz2 | |
(find_reloads): Properly account for cost when constant is forced to
memory to ensure same alternative chosen later.
From-SVN: r7319
Diffstat (limited to 'gcc/reload.c')
| -rw-r--r-- | gcc/reload.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/gcc/reload.c b/gcc/reload.c index cd4d754..afa1072 100644 --- a/gcc/reload.c +++ b/gcc/reload.c @@ -2530,6 +2530,9 @@ find_reloads (insn, replace, ind_levels, live_known, reload_reg_p) regardless of what the constraint says. */ int force_reload = 0; int offmemok = 0; + /* Nonzero if a constant forced into memory would be OK for this + operand. */ + int constmemok = 0; int earlyclobber = 0; /* If the operand is a SUBREG, extract @@ -2718,6 +2721,7 @@ find_reloads (insn, replace, ind_levels, live_known, reload_reg_p) win = 1; if (CONSTANT_P (operand)) badop = 0; + constmemok = 1; break; case '<': @@ -2784,6 +2788,7 @@ find_reloads (insn, replace, ind_levels, live_known, reload_reg_p) win = 1; if (CONSTANT_P (operand) || GET_CODE (operand) == MEM) badop = 0; + constmemok = 1; offmemok = 1; break; @@ -2917,6 +2922,8 @@ find_reloads (insn, replace, ind_levels, live_known, reload_reg_p) this_alternative_win[i] = 1; else { + int const_to_mem = 0; + this_alternative_offmemok[i] = offmemok; losers++; if (badop) @@ -2949,9 +2956,12 @@ find_reloads (insn, replace, ind_levels, live_known, reload_reg_p) && (PREFERRED_RELOAD_CLASS (operand, (enum reg_class) this_alternative[i]) == NO_REGS) - && this_alternative[i] != (int) NO_REGS && operand_mode[i] != VOIDmode) - losers++; + { + const_to_mem = 1; + if (this_alternative[i] != (int) NO_REGS) + losers++; + } /* If we can't reload this value at all, reject this alternative. Note that we could also lose due to @@ -2968,10 +2978,14 @@ find_reloads (insn, replace, ind_levels, live_known, reload_reg_p) since such reloads may be able to be eliminated later. If we are reloading a SCRATCH, we won't be generating any insns, just using a register, so it is also preferred. - So bump REJECT in other cases. */ + So bump REJECT in other cases. Don't do this in the + case where we are forcing a constant into memory and + it will then win since we don't want to have a different + alternative match then. */ if (! (GET_CODE (operand) == REG && REGNO (operand) >= FIRST_PSEUDO_REGISTER) - && GET_CODE (operand) != SCRATCH) + && GET_CODE (operand) != SCRATCH + && ! (const_to_mem && constmemok)) reject++; } |