From: Vladimir Makarov Date: Thu, 9 Jun 2016 21:28:31 +0000 (+0000) Subject: [Patch] PR70751, correct the cost for spilling non-pseudo into memory X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5f225ef44a2705e6dde737b03f69eba0739f8b5f;p=gcc.git [Patch] PR70751, correct the cost for spilling non-pseudo into memory PR rtl-optimization/70751 * lra-constraints.c (process_alt_operands): Recognize Non-pseudo spilled into memory. Co-Authored-By: Jiong Wang From-SVN: r237277 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 274155fe491..b27dd3f8df6 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2016-06-09 Vladimir Makarov + Jiong Wang + + PR rtl-optimization/70751 + * lra-constraints.c (process_alt_operands): Recognize Non-pseudo spilled + into memory. + 2016-06-09 Jonathan Yong <10walls@gmail.com> Revert: diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c index e4e6c8c47eb..bf08dce2e0a 100644 --- a/gcc/lra-constraints.c +++ b/gcc/lra-constraints.c @@ -2474,14 +2474,27 @@ process_alt_operands (int only_alternative) /* We are trying to spill pseudo into memory. It is usually more costly than moving to a hard register although it might takes the same number of - reloads. */ - if (no_regs_p && REG_P (op) && hard_regno[nop] >= 0) + reloads. + + Non-pseudo spill may happen also. Suppose a target allows both + register and memory in the operand constraint alternatives, + then it's typical that an eliminable register has a substition + of "base + offset" which can either be reloaded by a simple + "new_reg <= base + offset" which will match the register + constraint, or a similar reg addition followed by further spill + to and reload from memory which will match the memory + constraint, but this memory spill will be much more costly + usually. + + Code below increases the reject for both pseudo and non-pseudo + spill. */ + if (no_regs_p && !(REG_P (op) && hard_regno[nop] < 0)) { if (lra_dump_file != NULL) fprintf (lra_dump_file, - " %d Spill pseudo into memory: reject+=3\n", - nop); + " %d Spill %spseudo into memory: reject+=3\n", + nop, REG_P (op) ? "" : "Non-"); reject += 3; if (VECTOR_MODE_P (mode)) {