On Thu, 11 Oct 2018, Richard Biener wrote:
> On Thu, 11 Oct 2018, Richard Biener wrote:
>
> >
> > The following fixes vec_construct cost calculation to properly consider
> > that the inserts will happen to SSE regs thus forgo the multiplication
> > done in ix86_vec_cost which is passed the wrong mode. This gets rid of
> > the only call passing false to ix86_vec_cost (so consider the patch
> > amended to remove the arg if approved).
> >
> > Bootstrapped and tested on x86_64-unknown-linux-gnu.
> >
> > OK for trunk?
> >
> > I am considering to make the factor we apply in ix86_vec_cost
> > which currently depends on X86_TUNE_AVX128_OPTIMAL and
> > X86_TUNE_SSE_SPLIT_REGS part of the actual cost tables since
> > the reason we apply them are underlying CPU architecture details.
> > Was the original reason of doing the multiplication based on
> > those tunings to be able to "share" the same basic cost table
> > across architectures that differ in this important detail?
> > I see X86_TUNE_SSE_SPLIT_REGS is only used for m_ATHLON_K8
> > and X86_TUNE_AVX128_OPTIMAL is used for m_BDVER, m_BTVER2
> > and m_ZNVER1. Those all have (multiple) exclusive processor_cost_table
> > entries.
> >
> > As a first step I'd like to remove the use of ix86_vec_cost for
> > the entries that already have entries for multiple modes
> > (loads and stores) and apply the factor there. For example
> > Zen can do two 128bit loads per cycle but only one 128bit store.
> > With multiplying AVX256 costs by two we seem to cost sth like
> > # instructions to dispatch * instruction latency which is an
> > odd thing. I'd have expected # instructions to dispatch / instruction
> > throughput * instruction latency - so a AVX256 add would cost
> > the same as a AVX128 add, likewise for loads but stores would be
> > more expensive because of the throughput issue. This all
> > ignores resource utilization across multiple insns but that's
> > how the cost model works ...
>
> So like the following which removes the use of ix86_vec_cost
> for SSE loads and stores since we have per-mode costs already.
> I've applied the relevant factor to the individual cost tables
> (noting that for X86_TUNE_SSE_SPLIT_REGS we only apply the
> multiplication for size == 128, not size >= 128 ...)
>
> There's a ??? hunk in inline_memory_move_cost where we
> failed to apply the scaling thus in that place we'd now have
> a behavior change. Alternatively I could leave the cost
> tables unaltered if that costing part is more critical than
> the vectorizer one.
>
> I've also spotted, when reviewing ix86_vec_cost uses, a bug
> in ix86_rtx_cost which keys on SFmode which doesn't work
> for SSE modes, thus use GET_MODE_INNER.
>
> Also I've changed X86_TUNE_AVX128_OPTIMAL to also apply
> to BTVER1 - everywhere else we glob BTVER1 and BTVER2 so
> this must surely be a omission.
>
> Honza - is a patch like this OK?
PING. I dropped the config/i386/x86-tune.def hunk since btver1
doesn't have AVX.
Otherwise bootstrapped and tested on x86_64-unknown-linux-gnu.
Richard.
> Should I split out individual fixes to make bisection possible?
>
> Should I update the cost tables or instead change the vectorizer
> costing when considering the inline_memory_move_cost "issue"?
>
> Thanks,
> Richard.
>
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index 0cf4152acb2..f5392232f61 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -39432,6 +39432,7 @@ inline_memory_move_cost (machine_mode mode, enum
> reg_class regclass,
> int index = sse_store_index (mode);
> if (index == -1)
> return 100;
> + /* ??? */
> if (in == 2)
> return MAX (ix86_cost->sse_load [index], ix86_cost->sse_store
> [index]);
> return in ? ix86_cost->sse_load [index] : ix86_cost->sse_store [index];
> @@ -40183,7 +40181,8 @@ ix86_rtx_costs (rtx x, machine_mode mode, int
> outer_code_i, int opno,
> gcc_assert (TARGET_FMA || TARGET_FMA4 || TARGET_AVX512F);
>
> *total = ix86_vec_cost (mode,
> - mode == SFmode ? cost->fmass : cost->fmasd,
> + GET_MODE_INNER (mode) == SFmode
> + ? cost->fmass : cost->fmasd,
> true);
> *total += rtx_cost (XEXP (x, 1), mode, FMA, 1, speed);
>
> @@ -45122,18 +45121,14 @@ ix86_builtin_vectorization_cost (enum
> vect_cost_for_stmt type_of_cost,
> /* See PR82713 - we may end up being called on non-vector type. */
> if (index < 0)
> index = 2;
> - return ix86_vec_cost (mode,
> - COSTS_N_INSNS (ix86_cost->sse_load[index]) / 2,
> - true);
> + return COSTS_N_INSNS (ix86_cost->sse_load[index]) / 2;
>
> case vector_store:
> index = sse_store_index (mode);
> /* See PR82713 - we may end up being called on non-vector type. */
> if (index < 0)
> index = 2;
> - return ix86_vec_cost (mode,
> - COSTS_N_INSNS (ix86_cost->sse_store[index]) / 2,
> - true);
> + return COSTS_N_INSNS (ix86_cost->sse_store[index]) / 2;
>
> case vec_to_scalar:
> case scalar_to_vec:
> @@ -45146,20 +45141,14 @@ ix86_builtin_vectorization_cost (enum
> vect_cost_for_stmt type_of_cost,
> /* See PR82713 - we may end up being called on non-vector type. */
> if (index < 0)
> index = 2;
> - return ix86_vec_cost (mode,
> - COSTS_N_INSNS
> - (ix86_cost->sse_unaligned_load[index]) / 2,
> - true);
> + return COSTS_N_INSNS (ix86_cost->sse_unaligned_load[index]) / 2;
>
> case unaligned_store:
> index = sse_store_index (mode);
> /* See PR82713 - we may end up being called on non-vector type. */
> if (index < 0)
> index = 2;
> - return ix86_vec_cost (mode,
> - COSTS_N_INSNS
> - (ix86_cost->sse_unaligned_store[index]) / 2,
> - true);
> + return COSTS_N_INSNS (ix86_cost->sse_unaligned_store[index]) / 2;
>
> case vector_gather_load:
> return ix86_vec_cost (mode,
> diff --git a/gcc/config/i386/x86-tune-costs.h
> b/gcc/config/i386/x86-tune-costs.h
> index 9c8ae0a7841..59d0a8b17d0 100644
> --- a/gcc/config/i386/x86-tune-costs.h
> +++ b/gcc/config/i386/x86-tune-costs.h
> @@ -795,12 +795,12 @@ struct processor_costs athlon_cost = {
> {4, 4}, /* cost of storing MMX registers
> in SImode and DImode */
> 2, 4, 8, /* cost of moving XMM,YMM,ZMM register
> */
> - {4, 4, 6, 12, 24}, /* cost of loading SSE registers
> + {4, 4, 12, 12, 24}, /* cost of loading SSE registers
> in 32,64,128,256 and 512-bit */
> - {4, 4, 6, 12, 24}, /* cost of unaligned loads. */
> - {4, 4, 5, 10, 20}, /* cost of storing SSE registers
> + {4, 4, 12, 12, 24}, /* cost of unaligned loads. */
> + {4, 4, 10, 10, 20}, /* cost of storing SSE registers
> in 32,64,128,256 and 512-bit */
> - {4, 4, 5, 10, 20}, /* cost of unaligned stores. */
> + {4, 4, 10, 10, 20}, /* cost of unaligned stores. */
> 5, 5, /* SSE->integer and
> integer->SSE moves */
> 4, 4, /* Gather load static, per_elt.
> */
> 4, 4, /* Gather store static,
> per_elt. */
> @@ -891,12 +891,12 @@ struct processor_costs k8_cost = {
> {4, 4}, /* cost of storing MMX registers
> in SImode and DImode */
> 2, 4, 8, /* cost of moving XMM,YMM,ZMM register
> */
> - {4, 3, 6, 12, 24}, /* cost of loading SSE registers
> + {4, 3, 12, 12, 24}, /* cost of loading SSE registers
> in 32,64,128,256 and 512-bit */
> - {4, 3, 6, 12, 24}, /* cost of unaligned loads. */
> - {4, 4, 5, 10, 20}, /* cost of storing SSE registers
> + {4, 3, 12, 12, 24}, /* cost of unaligned loads. */
> + {4, 4, 10, 10, 20}, /* cost of storing SSE registers
> in 32,64,128,256 and 512-bit */
> - {4, 4, 5, 10, 20}, /* cost of unaligned stores. */
> + {4, 4, 10, 10, 20}, /* cost of unaligned stores. */
> 5, 5, /* SSE->integer and
> integer->SSE moves */
> 4, 4, /* Gather load static, per_elt.
> */
> 4, 4, /* Gather store static,
> per_elt. */
> @@ -1100,12 +1100,12 @@ const struct processor_costs bdver1_cost = {
> {10, 10}, /* cost of storing MMX registers
> in SImode and DImode */
> 2, 4, 8, /* cost of moving XMM,YMM,ZMM register
> */
> - {12, 12, 10, 20, 30}, /* cost of loading SSE registers
> + {12, 12, 10, 40, 60}, /* cost of loading SSE registers
> in 32,64,128,256 and 512-bit */
> - {12, 12, 10, 20, 30}, /* cost of unaligned loads. */
> - {10, 10, 10, 20, 30}, /* cost of storing SSE registers
> + {12, 12, 10, 40, 60}, /* cost of unaligned loads. */
> + {10, 10, 10, 40, 60}, /* cost of storing SSE registers
> in 32,64,128,256 and 512-bit */
> - {10, 10, 10, 20, 30}, /* cost of unaligned stores. */
> + {10, 10, 10, 40, 60}, /* cost of unaligned stores. */
> 16, 20, /* SSE->integer and integer->SSE moves
> */
> 12, 12, /* Gather load static, per_elt. */
> 10, 10, /* Gather store static, per_elt. */
> @@ -1203,12 +1203,12 @@ const struct processor_costs bdver2_cost = {
> {10, 10}, /* cost of storing MMX registers
> in SImode and DImode */
> 2, 4, 8, /* cost of moving XMM,YMM,ZMM register
> */
> - {12, 12, 10, 20, 30}, /* cost of loading SSE registers
> + {12, 12, 10, 40, 60}, /* cost of loading SSE registers
> in 32,64,128,256 and 512-bit */
> - {12, 12, 10, 20, 30}, /* cost of unaligned loads. */
> - {10, 10, 10, 20, 30}, /* cost of storing SSE registers
> + {12, 12, 10, 40, 60}, /* cost of unaligned loads. */
> + {10, 10, 10, 40, 60}, /* cost of storing SSE registers
> in 32,64,128,256 and 512-bit */
> - {10, 10, 10, 20, 30}, /* cost of unaligned stores. */
> + {10, 10, 10, 40, 60}, /* cost of unaligned stores. */
> 16, 20, /* SSE->integer and integer->SSE moves
> */
> 12, 12, /* Gather load static, per_elt. */
> 10, 10, /* Gather store static, per_elt. */
> @@ -1305,12 +1305,12 @@ struct processor_costs bdver3_cost = {
> {10, 10}, /* cost of storing MMX registers
> in SImode and DImode */
> 2, 4, 8, /* cost of moving XMM,YMM,ZMM register
> */
> - {12, 12, 10, 20, 30}, /* cost of loading SSE registers
> + {12, 12, 10, 40, 60}, /* cost of loading SSE registers
> in 32,64,128,256 and 512-bit */
> - {12, 12, 10, 20, 30}, /* cost of unaligned loads. */
> - {10, 10, 10, 20, 30}, /* cost of storing SSE registers
> + {12, 12, 10, 40, 60}, /* cost of unaligned loads. */
> + {10, 10, 10, 40, 60}, /* cost of storing SSE registers
> in 32,64,128,256 and 512-bit */
> - {10, 10, 10, 20, 30}, /* cost of unaligned stores. */
> + {10, 10, 10, 40, 60}, /* cost of unaligned stores. */
> 16, 20, /* SSE->integer and integer->SSE moves
> */
> 12, 12, /* Gather load static, per_elt. */
> 10, 10, /* Gather store static, per_elt. */
> @@ -1406,12 +1406,12 @@ struct processor_costs bdver4_cost = {
> {10, 10}, /* cost of storing MMX registers
> in SImode and DImode */
> 2, 4, 8, /* cost of moving XMM,YMM,ZMM register
> */
> - {12, 12, 10, 20, 30}, /* cost of loading SSE registers
> + {12, 12, 10, 40, 60}, /* cost of loading SSE registers
> in 32,64,128,256 and 512-bit */
> - {12, 12, 10, 20, 30}, /* cost of unaligned loads. */
> - {10, 10, 10, 20, 30}, /* cost of storing SSE registers
> + {12, 12, 10, 40, 60}, /* cost of unaligned loads. */
> + {10, 10, 10, 40, 60}, /* cost of storing SSE registers
> in 32,64,128,256 and 512-bit */
> - {10, 10, 10, 20, 30}, /* cost of unaligned stores. */
> + {10, 10, 10, 40, 60}, /* cost of unaligned stores. */
> 16, 20, /* SSE->integer and integer->SSE moves
> */
> 12, 12, /* Gather load static, per_elt. */
> 10, 10, /* Gather store static, per_elt. */
> @@ -1518,12 +1518,12 @@ struct processor_costs znver1_cost = {
> {8, 8}, /* cost of storing MMX registers
> in SImode and DImode. */
> 2, 3, 6, /* cost of moving XMM,YMM,ZMM register.
> */
> - {6, 6, 6, 6, 12}, /* cost of loading SSE registers
> + {6, 6, 6, 12, 24}, /* cost of loading SSE registers
> in 32,64,128,256 and 512-bit. */
> - {6, 6, 6, 6, 12}, /* cost of unaligned loads. */
> - {8, 8, 8, 8, 16}, /* cost of storing SSE registers
> + {6, 6, 6, 12, 24}, /* cost of unaligned loads. */
> + {8, 8, 8, 16, 32}, /* cost of storing SSE registers
> in 32,64,128,256 and 512-bit. */
> - {8, 8, 8, 8, 16}, /* cost of unaligned stores. */
> + {8, 8, 8, 16, 32}, /* cost of unaligned stores. */
> 6, 6, /* SSE->integer and
> integer->SSE moves. */
> /* VGATHERDPD is 23 uops and throughput is 9, VGATHERDPD is 35 uops,
> throughput 12. Approx 9 uops do not depend on vector size and every
> load
> @@ -1726,12 +1726,12 @@ const struct processor_costs btver1_cost = {
> {12, 12}, /* cost of storing MMX registers
> in SImode and DImode */
> 2, 4, 8, /* cost of moving XMM,YMM,ZMM register
> */
> - {10, 10, 12, 24, 48}, /* cost of loading SSE registers
> + {10, 10, 12, 48, 96}, /* cost of loading SSE registers
> in 32,64,128,256 and 512-bit */
> - {10, 10, 12, 24, 48}, /* cost of unaligned loads. */
> - {10, 10, 12, 24, 48}, /* cost of storing SSE registers
> + {10, 10, 12, 48, 96}, /* cost of unaligned loads. */
> + {10, 10, 12, 48, 96}, /* cost of storing SSE registers
> in 32,64,128,256 and 512-bit */
> - {10, 10, 12, 24, 48}, /* cost of unaligned stores. */
> + {10, 10, 12, 48, 96}, /* cost of unaligned stores. */
> 14, 14, /* SSE->integer and integer->SSE moves
> */
> 10, 10, /* Gather load static, per_elt. */
> 10, 10, /* Gather store static, per_elt. */
> @@ -1817,12 +1817,12 @@ const struct processor_costs btver2_cost = {
> {12, 12}, /* cost of storing MMX registers
> in SImode and DImode */
> 2, 4, 8, /* cost of moving XMM,YMM,ZMM register
> */
> - {10, 10, 12, 24, 48}, /* cost of loading SSE registers
> + {10, 10, 12, 48, 96}, /* cost of loading SSE registers
> in 32,64,128,256 and 512-bit */
> - {10, 10, 12, 24, 48}, /* cost of unaligned loads. */
> - {10, 10, 12, 24, 48}, /* cost of storing SSE registers
> + {10, 10, 12, 48, 96}, /* cost of unaligned loads. */
> + {10, 10, 12, 48, 96}, /* cost of storing SSE registers
> in 32,64,128,256 and 512-bit */
> - {10, 10, 12, 24, 48}, /* cost of unaligned stores. */
> + {10, 10, 12, 48, 96}, /* cost of unaligned stores. */
> 14, 14, /* SSE->integer and integer->SSE moves
> */
> 10, 10, /* Gather load static, per_elt. */
> 10, 10, /* Gather store static, per_elt. */
> diff --git a/gcc/config/i386/x86-tune.def b/gcc/config/i386/x86-tune.def
> index a46450ad99d..ad8661075aa 100644
> --- a/gcc/config/i386/x86-tune.def
> +++ b/gcc/config/i386/x86-tune.def
> @@ -441,7 +441,7 @@ DEF_TUNE (X86_TUNE_AVX256_UNALIGNED_STORE_OPTIMAL,
> "256_unaligned_store_optimal"
>
> /* X86_TUNE_AVX128_OPTIMAL: Enable 128-bit AVX instruction generation for
> the auto-vectorizer. */
> -DEF_TUNE (X86_TUNE_AVX128_OPTIMAL, "avx128_optimal", m_BDVER | m_BTVER2
> +DEF_TUNE (X86_TUNE_AVX128_OPTIMAL, "avx128_optimal", m_BDVER | m_BTVER
> | m_ZNVER1)
>
> /* X86_TUNE_AVX256_OPTIMAL: Use 256-bit AVX instructions instead of 512-bit
> AVX
>
>
--
Richard Biener <[email protected]>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
