From ab03c0d5753549f1a78eeb706510b55fb97c8651 Mon Sep 17 00:00:00 2001 From: Jan Hubicka Date: Thu, 18 Mar 2021 17:15:34 +0100 Subject: [PATCH] Fix idiv latencies for znver3 update costs of integer divides to match actual latencies (the scheduler model already does the right thing). It is essentially no-op, since we end up expanding idiv for all sensible constants, so this only may end up disabling vectorization in some cases, but I did not find any such examples. However in general it is better ot have actual latencies than random numbers. gcc/ChangeLog: 2021-03-18 Jan Hubicka * config/i386/x86-tune-costs.h (struct processor_costs): Fix costs of integer divides1. --- gcc/config/i386/x86-tune-costs.h | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/gcc/config/i386/x86-tune-costs.h b/gcc/config/i386/x86-tune-costs.h index db03738313e7..58b3b81985ba 100644 --- a/gcc/config/i386/x86-tune-costs.h +++ b/gcc/config/i386/x86-tune-costs.h @@ -1741,13 +1741,11 @@ struct processor_costs znver3_cost = { COSTS_N_INSNS (3)}, /* other. */ 0, /* cost of multiply per each bit set. */ - /* Depending on parameters, idiv can get faster on ryzen. This is upper - bound. */ - {COSTS_N_INSNS (16), /* cost of a divide/mod for QI. */ - COSTS_N_INSNS (22), /* HI. */ - COSTS_N_INSNS (30), /* SI. */ - COSTS_N_INSNS (45), /* DI. */ - COSTS_N_INSNS (45)}, /* other. */ + {COSTS_N_INSNS (9), /* cost of a divide/mod for QI. */ + COSTS_N_INSNS (10), /* HI. */ + COSTS_N_INSNS (12), /* SI. */ + COSTS_N_INSNS (17), /* DI. */ + COSTS_N_INSNS (17)}, /* other. */ COSTS_N_INSNS (1), /* cost of movsx. */ COSTS_N_INSNS (1), /* cost of movzx. */ 8, /* "large" insn. */ -- 2.47.3