Hi,
this patch updates znver2 costs to match reality. In particular we
re-benchmarked memcpy strategies and it looks that glibc now wins even
for relatively small blocks.
Moreover I updated costs of moves to reflect that znver2 has 256 vector
paths and faster multiplication.
Bootstrapped/regtested x86_64-linux, comitted.
Honza
* x86-tune-costs.h (znver2_memcpy): Update.
(znver2_costs): Update 256 bit SSE costs and multiplication.
Index: config/i386/x86-tune-costs.h
===================================================================
--- config/i386/x86-tune-costs.h (revision 273727)
+++ config/i386/x86-tune-costs.h (working copy)
@@ -1279,12 +1279,12 @@ struct processor_costs znver1_cost = {
static stringop_algs znver2_memcpy[2] = {
{libcall, {{6, loop, false}, {14, unrolled_loop, false},
{-1, rep_prefix_4_byte, false}}},
- {libcall, {{16, loop, false}, {8192, rep_prefix_8_byte, false},
+ {libcall, {{16, loop, false}, {64, rep_prefix_4_byte, false},
{-1, libcall, false}}}};
static stringop_algs znver2_memset[2] = {
{libcall, {{8, loop, false}, {24, unrolled_loop, false},
{2048, rep_prefix_4_byte, false}, {-1, libcall, false}}},
- {libcall, {{48, unrolled_loop, false}, {8192, rep_prefix_8_byte, false},
+ {libcall, {{24, rep_prefix_4_byte, false}, {128, rep_prefix_8_byte, false},
{-1, libcall, false}}}};
struct processor_costs znver2_cost = {
@@ -1335,11 +1335,11 @@ struct processor_costs znver2_cost = {
in SImode and DImode. */
{8, 8}, /* cost of storing MMX registers
in SImode and DImode. */
- 2, 3, 6, /* cost of moving XMM,YMM,ZMM
+ 2, 2, 3, /* cost of moving XMM,YMM,ZMM
register. */
- {6, 6, 6, 10, 20}, /* cost of loading SSE registers
+ {6, 6, 6, 6, 12}, /* cost of loading SSE registers
in 32,64,128,256 and 512-bit. */
- {6, 6, 6, 10, 20}, /* cost of unaligned loads. */
+ {6, 6, 6, 6, 12}, /* cost of unaligned loads. */
{8, 8, 8, 8, 16}, /* cost of storing SSE registers
in 32,64,128,256 and 512-bit. */
{8, 8, 8, 8, 16}, /* cost of unaligned stores. */
@@ -1372,7 +1372,7 @@ struct processor_costs znver2_cost = {
COSTS_N_INSNS (1), /* cost of cheap SSE instruction. */
COSTS_N_INSNS (3), /* cost of ADDSS/SD SUBSS/SD insns. */
COSTS_N_INSNS (3), /* cost of MULSS instruction. */
- COSTS_N_INSNS (4), /* cost of MULSD instruction. */
+ COSTS_N_INSNS (3), /* cost of MULSD instruction. */
COSTS_N_INSNS (5), /* cost of FMA SS instruction. */
COSTS_N_INSNS (5), /* cost of FMA SD instruction. */
COSTS_N_INSNS (10), /* cost of DIVSS instruction. */
