diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/config/i386/i386-features.c | 38 | ||||
| -rw-r--r-- | gcc/config/i386/i386.c | 2 | ||||
| -rw-r--r-- | gcc/config/i386/i386.h | 5 |
3 files changed, 38 insertions, 7 deletions
diff --git a/gcc/config/i386/i386-features.c b/gcc/config/i386/i386-features.c index d9c6652..5a99ea7 100644 --- a/gcc/config/i386/i386-features.c +++ b/gcc/config/i386/i386-features.c @@ -610,12 +610,40 @@ general_scalar_chain::compute_convert_gain () case CONST_INT: if (REG_P (dst)) - /* DImode can be immediate for TARGET_64BIT and SImode always. */ - igain += m * COSTS_N_INSNS (1); + { + if (optimize_insn_for_size_p ()) + { + /* xor (2 bytes) vs. xorps (3 bytes). */ + if (src == const0_rtx) + igain -= COSTS_N_BYTES (1); + /* movdi_internal vs. movv2di_internal. */ + /* => mov (5 bytes) vs. movaps (7 bytes). */ + else if (x86_64_immediate_operand (src, SImode)) + igain -= COSTS_N_BYTES (2); + else + /* ??? Larger immediate constants are placed in the + constant pool, where the size benefit/impact of + STV conversion is affected by whether and how + often each constant pool entry is shared/reused. + The value below is empirically derived from the + CSiBE benchmark (and the optimal value may drift + over time). */ + igain += COSTS_N_BYTES (0); + } + else + { + /* DImode can be immediate for TARGET_64BIT + and SImode always. */ + igain += m * COSTS_N_INSNS (1); + igain -= vector_const_cost (src); + } + } else if (MEM_P (dst)) - igain += (m * ix86_cost->int_store[2] - - ix86_cost->sse_store[sse_cost_idx]); - igain -= vector_const_cost (src); + { + igain += (m * ix86_cost->int_store[2] + - ix86_cost->sse_store[sse_cost_idx]); + igain -= vector_const_cost (src); + } break; default: diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 46844fa..5bff131 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -19982,8 +19982,6 @@ ix86_division_cost (const struct processor_costs *cost, return cost->divide[MODE_INDEX (mode)]; } -#define COSTS_N_BYTES(N) ((N) * 2) - /* Return cost of shift in MODE. If CONSTANT_OP1 is true, the op1 value is known and set in OP1_VAL. AND_IN_OP1 specify in op1 is result of and and SHIFT_AND_TRUNCATE diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h index 8aba86d..11ac8d0 100644 --- a/gcc/config/i386/i386.h +++ b/gcc/config/i386/i386.h @@ -88,6 +88,11 @@ struct stringop_algs } size [MAX_STRINGOP_ALGS]; }; +/* Analog of COSTS_N_INSNS when optimizing for size. */ +#ifndef COSTS_N_BYTES +#define COSTS_N_BYTES(N) ((N) * 2) +#endif + /* Define the specific costs for a given cpu. NB: hard_register is used by TARGET_REGISTER_MOVE_COST and TARGET_MEMORY_MOVE_COST to compute hard register move costs by register allocator. Relative costs of |