From 66574c5374ecbd358e68d63922927fc03f2f232a Mon Sep 17 00:00:00 2001 From: Hongtao Liu Date: Fri, 14 Jun 2019 15:41:43 +0000 Subject: [PATCH] i386: Update SSE <-> integer move costs Since inline_secondary_memory_needed has /* ??? This is a lie. We do have moves between mmx/general, and for mmx/sse2. But by saying we need secondary memory we discourage the register allocator from using the mmx registers unless needed. */ if (MMX_CLASS_P (class1) != MMX_CLASS_P (class2)) return true; moves between MMX and non-MMX units require secondary memory. There is no need to check moves between MMX and integer units. struct processor_costs has: const int mmxsse_to_integer; /* cost of moving mmxsse register to integer. */ const int ssemmx_to_integer; /* cost of moving integer to mmxsse register. */ This patch also renames mmxsse_to_integer to sse_to_integer and ssemmx_to_integer to integer_to_sse. Tested on Linux/x86-64. PR target/90877 * config/i386/i386-features.c (dimode_scalar_chain::compute_convert_gain): Replace mmxsse_to_integer with sse_to_integer. * config/i386/i386.c (ix86_register_move_cost): Verify that moves between MMX and non-MMX units require secondary memory. Correct costs of moves between SSE and integer units. * config/i386/i386.h (processor_costs): Rename cost of moving SSE register to integer to sse_to_integer. Rename cost of moving integer register to SSE to integer_to_sse. From-SVN: r272294 --- gcc/ChangeLog | 12 ++++++++++++ gcc/config/i386/i386-features.c | 2 +- gcc/config/i386/i386.c | 17 ++++++++++------- gcc/config/i386/i386.h | 5 ++--- 4 files changed, 25 insertions(+), 11 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index f98290188c9..deba7606659 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,15 @@ +2019-06-14 Hongtao Liu + + PR target/90877 + * config/i386/i386-features.c + (dimode_scalar_chain::compute_convert_gain): Replace + mmxsse_to_integer with sse_to_integer. + * config/i386/i386.c (ix86_register_move_cost): Verify that + moves between MMX and non-MMX units require secondary memory. + Correct costs of moves between SSE and integer units. + * config/i386/i386.h (processor_costs): Rename cost of moving + SSE register to integer to sse_to_integer. Rename cost of + 2019-06-14 Matt Thomas Matthew Green Nick Hudson diff --git a/gcc/config/i386/i386-features.c b/gcc/config/i386/i386-features.c index 51f88ae4d8a..2eac8f715bb 100644 --- a/gcc/config/i386/i386-features.c +++ b/gcc/config/i386/i386-features.c @@ -554,7 +554,7 @@ dimode_scalar_chain::compute_convert_gain () fprintf (dump_file, " Instruction conversion gain: %d\n", gain); EXECUTE_IF_SET_IN_BITMAP (defs_conv, 0, insn_uid, bi) - cost += DF_REG_DEF_COUNT (insn_uid) * ix86_cost->mmxsse_to_integer; + cost += DF_REG_DEF_COUNT (insn_uid) * ix86_cost->sse_to_integer; if (dump_file) fprintf (dump_file, " Registers conversion cost: %d\n", cost); diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 2eddea56b2e..941e208bcf0 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -18633,18 +18633,21 @@ ix86_register_move_cost (machine_mode mode, reg_class_t class1_i, return cost; } - /* Moves between SSE/MMX and integer unit are expensive. */ - if (MMX_CLASS_P (class1) != MMX_CLASS_P (class2) - || SSE_CLASS_P (class1) != SSE_CLASS_P (class2)) + /* Moves between MMX and non-MMX units require secondary memory. */ + if (MMX_CLASS_P (class1) != MMX_CLASS_P (class2)) + gcc_unreachable (); + + /* Moves between SSE and integer units are expensive. */ + if (SSE_CLASS_P (class1) != SSE_CLASS_P (class2)) /* ??? By keeping returned value relatively high, we limit the number - of moves between integer and MMX/SSE registers for all targets. + of moves between integer and SSE registers for all targets. Additionally, high value prevents problem with x86_modes_tieable_p(), - where integer modes in MMX/SSE registers are not tieable + where integer modes in SSE registers are not tieable because of missing QImode and HImode moves to, from or between MMX/SSE registers. */ - return MAX (8, MMX_CLASS_P (class1) || MMX_CLASS_P (class2) - ? ix86_cost->mmxsse_to_integer : ix86_cost->ssemmx_to_integer); + return MAX (8, SSE_CLASS_P (class1) + ? ix86_cost->sse_to_integer : ix86_cost->integer_to_sse); if (MAYBE_FLOAT_CLASS_P (class1)) return ix86_cost->fp_move; diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h index 01213ccb82c..0ac5d651823 100644 --- a/gcc/config/i386/i386.h +++ b/gcc/config/i386/i386.h @@ -276,9 +276,8 @@ struct processor_costs { const int sse_store[5]; /* cost of storing SSE register in SImode, DImode and TImode. */ const int sse_unaligned_store[5];/* cost of unaligned store. */ - const int mmxsse_to_integer; /* cost of moving mmxsse register to - integer. */ - const int ssemmx_to_integer; /* cost of moving integer to mmxsse register. */ + const int sse_to_integer; /* cost of moving SSE register to integer. */ + const int integer_to_sse; /* cost of moving integer register to SSE. */ const int gather_static, gather_per_elt; /* Cost of gather load is computed as static + per_item * nelts. */ const int scatter_static, scatter_per_elt; /* Cost of gather store is -- 2.30.2