[PATCH] PR target/66749: Add -march=iamcu to optimize for IA MCU
H.J. Lu
hjl.tools@gmail.com
Mon Jul 6 13:28:00 GMT 2015
IA MCU is based on Intel Pentium ISA without x87 and passing parameters
in registers. We want to optimize for IA MCU without changing existing
Pentium codegen. This patch adds PROCESSOR_IAMCU for -march=iamcu,
which is based on -march=pentium with updated cost tables.
OK for trunk?
Thanks.
H.J.
--
gcc/
PR target/66749
* config/i386/i386.c (iamcu_cost): New.
(m_IAMCU): Likewise.
(initial_ix86_arch_features): Disable X86_ARCH_CMOV for m_IAMCU.
(processor_target_table): Add an entry for "iamcu".
(processor_alias_table): Likewise.
(ix86_issue_rate): Handle PROCESSOR_IAMCU.
(ix86_adjust_cost): Likewise.
(ia32_multipass_dfa_lookahead): Likewise.
* config/i386/i386.h (processor_type): Add PROCESSOR_IAMCU.
* config/i386/x86-tune.def: Updated for m_IAMCU.
gcc/testsuite/
PR target/66749
* gcc.target/i386/pr66749.c: New test.
---
gcc/config/i386/i386.c | 76 ++++++++++++++++++++++++++++++++-
gcc/config/i386/i386.h | 1 +
gcc/config/i386/x86-tune.def | 36 +++++++++-------
gcc/testsuite/gcc.target/i386/pr66749.c | 14 ++++++
4 files changed, 111 insertions(+), 16 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr66749.c
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 7d26e8c..98250c4 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -426,6 +426,74 @@ struct processor_costs pentium_cost = {
1, /* cond_not_taken_branch_cost. */
};
+static const
+struct processor_costs iamcu_cost = {
+ COSTS_N_INSNS (1), /* cost of an add instruction */
+ COSTS_N_INSNS (1) + 1, /* cost of a lea instruction */
+ COSTS_N_INSNS (4), /* variable shift costs */
+ COSTS_N_INSNS (1), /* constant shift costs */
+ {COSTS_N_INSNS (11), /* cost of starting multiply for QI */
+ COSTS_N_INSNS (11), /* HI */
+ COSTS_N_INSNS (11), /* SI */
+ COSTS_N_INSNS (11), /* DI */
+ COSTS_N_INSNS (11)}, /* other */
+ 0, /* cost of multiply per each bit set */
+ {COSTS_N_INSNS (25), /* cost of a divide/mod for QI */
+ COSTS_N_INSNS (25), /* HI */
+ COSTS_N_INSNS (25), /* SI */
+ COSTS_N_INSNS (25), /* DI */
+ COSTS_N_INSNS (25)}, /* other */
+ COSTS_N_INSNS (3), /* cost of movsx */
+ COSTS_N_INSNS (2), /* cost of movzx */
+ 8, /* "large" insn */
+ 6, /* MOVE_RATIO */
+ 6, /* cost for loading QImode using movzbl */
+ {2, 4, 2}, /* cost of loading integer registers
+ in QImode, HImode and SImode.
+ Relative to reg-reg move (2). */
+ {2, 4, 2}, /* cost of storing integer registers */
+ 2, /* cost of reg,reg fld/fst */
+ {2, 2, 6}, /* cost of loading fp registers
+ in SFmode, DFmode and XFmode */
+ {4, 4, 6}, /* cost of storing fp registers
+ in SFmode, DFmode and XFmode */
+ 8, /* cost of moving MMX register */
+ {8, 8}, /* cost of loading MMX registers
+ in SImode and DImode */
+ {8, 8}, /* cost of storing MMX registers
+ in SImode and DImode */
+ 2, /* cost of moving SSE register */
+ {4, 8, 16}, /* cost of loading SSE registers
+ in SImode, DImode and TImode */
+ {4, 8, 16}, /* cost of storing SSE registers
+ in SImode, DImode and TImode */
+ 3, /* MMX or SSE register to integer */
+ 8, /* size of l1 cache. */
+ 8, /* size of l2 cache */
+ 0, /* size of prefetch block */
+ 0, /* number of parallel prefetches */
+ 2, /* Branch cost */
+ COSTS_N_INSNS (3), /* cost of FADD and FSUB insns. */
+ COSTS_N_INSNS (3), /* cost of FMUL instruction. */
+ COSTS_N_INSNS (39), /* cost of FDIV instruction. */
+ COSTS_N_INSNS (1), /* cost of FABS instruction. */
+ COSTS_N_INSNS (1), /* cost of FCHS instruction. */
+ COSTS_N_INSNS (70), /* cost of FSQRT instruction. */
+ pentium_memcpy,
+ pentium_memset,
+ 1, /* scalar_stmt_cost. */
+ 1, /* scalar load_cost. */
+ 1, /* scalar_store_cost. */
+ 1, /* vec_stmt_cost. */
+ 1, /* vec_to_scalar_cost. */
+ 1, /* scalar_to_vec_cost. */
+ 1, /* vec_align_load_cost. */
+ 2, /* vec_unalign_load_cost. */
+ 1, /* vec_store_cost. */
+ 3, /* cond_taken_branch_cost. */
+ 1, /* cond_not_taken_branch_cost. */
+};
+
/* PentiumPro has optimized rep instructions for blocks aligned by 8 bytes
(we ensure the alignment). For small blocks inline loop is still a
noticeable win, for bigger blocks either rep movsl or rep movsb is
@@ -2027,6 +2095,7 @@ const struct processor_costs *ix86_cost = &pentium_cost;
#define m_386 (1<<PROCESSOR_I386)
#define m_486 (1<<PROCESSOR_I486)
#define m_PENT (1<<PROCESSOR_PENTIUM)
+#define m_IAMCU (1<<PROCESSOR_IAMCU)
#define m_PPRO (1<<PROCESSOR_PENTIUMPRO)
#define m_PENT4 (1<<PROCESSOR_PENTIUM4)
#define m_NOCONA (1<<PROCESSOR_NOCONA)
@@ -2086,7 +2155,7 @@ unsigned char ix86_arch_features[X86_ARCH_LAST];
ix86_arch_features based on the processor mask. */
static unsigned int initial_ix86_arch_features[X86_ARCH_LAST] = {
/* X86_ARCH_CMOV: Conditional move was added for pentiumpro. */
- ~(m_386 | m_486 | m_PENT | m_K6),
+ ~(m_386 | m_486 | m_PENT | m_IAMCU | m_K6),
/* X86_ARCH_CMPXCHG: Compare and exchange was added for 80486. */
~m_386,
@@ -2497,6 +2566,7 @@ static const struct ptt processor_target_table[PROCESSOR_max] =
{"i386", &i386_cost, 4, 3, 4, 3, 4},
{"i486", &i486_cost, 16, 15, 16, 15, 16},
{"pentium", &pentium_cost, 16, 7, 16, 7, 16},
+ {"iamcu", &iamcu_cost, 16, 7, 16, 7, 16},
{"pentiumpro", &pentiumpro_cost, 16, 15, 16, 10, 16},
{"pentium4", &pentium4_cost, 0, 0, 0, 0, 0},
{"nocona", &nocona_cost, 0, 0, 0, 0, 0},
@@ -3246,6 +3316,7 @@ ix86_option_override_internal (bool main_args_p,
{"i486", PROCESSOR_I486, CPU_NONE, 0},
{"i586", PROCESSOR_PENTIUM, CPU_PENTIUM, 0},
{"pentium", PROCESSOR_PENTIUM, CPU_PENTIUM, 0},
+ {"iamcu", PROCESSOR_IAMCU, CPU_PENTIUM, 0},
{"pentium-mmx", PROCESSOR_PENTIUM, CPU_PENTIUM, PTA_MMX},
{"winchip-c6", PROCESSOR_I486, CPU_NONE, PTA_MMX},
{"winchip2", PROCESSOR_I486, CPU_NONE, PTA_MMX | PTA_3DNOW | PTA_PRFCHW},
@@ -26138,6 +26209,7 @@ ix86_issue_rate (void)
switch (ix86_tune)
{
case PROCESSOR_PENTIUM:
+ case PROCESSOR_IAMCU:
case PROCESSOR_BONNELL:
case PROCESSOR_SILVERMONT:
case PROCESSOR_KNL:
@@ -26324,6 +26396,7 @@ ix86_adjust_cost (rtx_insn *insn, rtx link, rtx_insn *dep_insn, int cost)
switch (ix86_tune)
{
case PROCESSOR_PENTIUM:
+ case PROCESSOR_IAMCU:
/* Address Generation Interlock adds a cycle of latency. */
if (insn_type == TYPE_LEA)
{
@@ -26533,6 +26606,7 @@ ia32_multipass_dfa_lookahead (void)
switch (ix86_tune)
{
case PROCESSOR_PENTIUM:
+ case PROCESSOR_IAMCU:
return 2;
case PROCESSOR_PENTIUMPRO:
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index d710b3d..f357e79 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -2266,6 +2266,7 @@ enum processor_type
PROCESSOR_I386, /* 80386 */
PROCESSOR_I486, /* 80486DX, 80486SX, 80486DX[24] */
PROCESSOR_PENTIUM,
+ PROCESSOR_IAMCU,
PROCESSOR_PENTIUMPRO,
PROCESSOR_PENTIUM4,
PROCESSOR_NOCONA,
diff --git a/gcc/config/i386/x86-tune.def b/gcc/config/i386/x86-tune.def
index bb3209d..42a560b 100644
--- a/gcc/config/i386/x86-tune.def
+++ b/gcc/config/i386/x86-tune.def
@@ -40,8 +40,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
/* X86_TUNE_SCHEDULE: Enable scheduling. */
DEF_TUNE (X86_TUNE_SCHEDULE, "schedule",
- m_PENT | m_PPRO | m_CORE_ALL | m_BONNELL | m_SILVERMONT | m_INTEL
- | m_KNL | m_K6_GEODE | m_AMD_MULTIPLE | m_GENERIC)
+ m_PENT | m_IAMCU | m_PPRO | m_CORE_ALL | m_BONNELL | m_SILVERMONT
+ | m_INTEL | m_KNL | m_K6_GEODE | m_AMD_MULTIPLE | m_GENERIC)
/* X86_TUNE_PARTIAL_REG_DEPENDENCY: Enable more register renaming
on modern chips. Preffer stores affecting whole integer register
@@ -172,19 +172,21 @@ DEF_TUNE (X86_TUNE_PUSH_MEMORY, "push_memory",
/* X86_TUNE_SINGLE_PUSH: Enable if single push insn is preferred
over esp subtraction. */
DEF_TUNE (X86_TUNE_SINGLE_PUSH, "single_push", m_386 | m_486 | m_PENT
- | m_K6_GEODE)
+ | m_IAMCU | m_K6_GEODE)
/* X86_TUNE_DOUBLE_PUSH. Enable if double push insn is preferred
over esp subtraction. */
-DEF_TUNE (X86_TUNE_DOUBLE_PUSH, "double_push", m_PENT | m_K6_GEODE)
+DEF_TUNE (X86_TUNE_DOUBLE_PUSH, "double_push", m_PENT | m_IAMCU
+ | m_K6_GEODE)
/* X86_TUNE_SINGLE_POP: Enable if single pop insn is preferred
over esp addition. */
-DEF_TUNE (X86_TUNE_SINGLE_POP, "single_pop", m_386 | m_486 | m_PENT | m_PPRO)
+DEF_TUNE (X86_TUNE_SINGLE_POP, "single_pop", m_386 | m_486 | m_PENT
+ | m_IAMCU | m_PPRO)
/* X86_TUNE_DOUBLE_POP: Enable if double pop insn is preferred
over esp addition. */
-DEF_TUNE (X86_TUNE_DOUBLE_POP, "double_pop", m_PENT)
+DEF_TUNE (X86_TUNE_DOUBLE_POP, "double_pop", m_PENT | m_IAMCU)
/*****************************************************************************/
/* Branch predictor tuning */
@@ -224,7 +226,7 @@ DEF_TUNE (X86_TUNE_LCP_STALL, "lcp_stall", m_CORE_ALL | m_GENERIC)
/* X86_TUNE_READ_MODIFY: Enable use of read-modify instructions such
as "add mem, reg". */
-DEF_TUNE (X86_TUNE_READ_MODIFY, "read_modify", ~(m_PENT | m_PPRO))
+DEF_TUNE (X86_TUNE_READ_MODIFY, "read_modify", ~(m_PENT | m_IAMCU | m_PPRO))
/* X86_TUNE_USE_INCDEC: Enable use of inc/dec instructions. */
DEF_TUNE (X86_TUNE_USE_INCDEC, "use_incdec",
@@ -284,7 +286,8 @@ DEF_TUNE (X86_TUNE_USE_SAHF, "use_sahf",
/* X86_TUNE_USE_CLTD: Controls use of CLTD and CTQO instructions. */
DEF_TUNE (X86_TUNE_USE_CLTD, "use_cltd",
- ~(m_PENT | m_BONNELL | m_SILVERMONT | m_KNL | m_INTEL | m_K6))
+ ~(m_PENT | m_IAMCU | m_BONNELL | m_SILVERMONT | m_KNL | m_INTEL
+ | m_K6))
/* X86_TUNE_USE_BT: Enable use of BT (bit test) instructions. */
DEF_TUNE (X86_TUNE_USE_BT, "use_bt",
@@ -304,8 +307,8 @@ DEF_TUNE (X86_TUNE_USE_HIMODE_FIOP, "use_himode_fiop",
/* X86_TUNE_USE_SIMODE_FIOP: Enables use of x87 instructions with 32bit
integer operand. */
DEF_TUNE (X86_TUNE_USE_SIMODE_FIOP, "use_simode_fiop",
- ~(m_PENT | m_PPRO | m_CORE_ALL | m_BONNELL | m_SILVERMONT
- | m_KNL | m_INTEL | m_AMD_MULTIPLE | m_GENERIC))
+ ~(m_PENT | m_IAMCU | m_PPRO | m_CORE_ALL | m_BONNELL
+ | m_SILVERMONT | m_KNL | m_INTEL | m_AMD_MULTIPLE | m_GENERIC))
/* X86_TUNE_USE_FFREEP: Use freep instruction instead of fstp. */
DEF_TUNE (X86_TUNE_USE_FFREEP, "use_ffreep", m_AMD_MULTIPLE)
@@ -444,7 +447,8 @@ DEF_TUNE (X86_TUNE_SHIFT1, "shift1", ~m_486)
/* X86_TUNE_ZERO_EXTEND_WITH_AND: Use AND instruction instead
of mozbl/movwl. */
-DEF_TUNE (X86_TUNE_ZERO_EXTEND_WITH_AND, "zero_extend_with_and", m_486 | m_PENT)
+DEF_TUNE (X86_TUNE_ZERO_EXTEND_WITH_AND, "zero_extend_with_and",
+ m_486 | m_PENT | m_IAMCU)
/* X86_TUNE_PROMOTE_HIMODE_IMUL: Modern CPUs have same latency for HImode
and SImode multiply, but 386 and 486 do HImode multiply faster. */
@@ -454,19 +458,21 @@ DEF_TUNE (X86_TUNE_PROMOTE_HIMODE_IMUL, "promote_himode_imul",
/* X86_TUNE_FAST_PREFIX: Enable demoting some 32bit or 64bit arithmetic
into 16bit/8bit when resulting sequence is shorter. For example
for "and $-65536, reg" to 16bit store of 0. */
-DEF_TUNE (X86_TUNE_FAST_PREFIX, "fast_prefix", ~(m_386 | m_486 | m_PENT))
+DEF_TUNE (X86_TUNE_FAST_PREFIX, "fast_prefix",
+ ~(m_386 | m_486 | m_PENT | m_IAMCU))
/* X86_TUNE_READ_MODIFY_WRITE: Enable use of read modify write instructions
such as "add $1, mem". */
-DEF_TUNE (X86_TUNE_READ_MODIFY_WRITE, "read_modify_write", ~m_PENT)
+DEF_TUNE (X86_TUNE_READ_MODIFY_WRITE, "read_modify_write",
+ ~(m_PENT | m_IAMCU))
/* X86_TUNE_MOVE_M1_VIA_OR: On pentiums, it is faster to load -1 via OR
than a MOV. */
-DEF_TUNE (X86_TUNE_MOVE_M1_VIA_OR, "move_m1_via_or", m_PENT)
+DEF_TUNE (X86_TUNE_MOVE_M1_VIA_OR, "move_m1_via_or", m_PENT | m_IAMCU)
/* X86_TUNE_NOT_UNPAIRABLE: NOT is not pairable on Pentium, while XOR is,
but one byte longer. */
-DEF_TUNE (X86_TUNE_NOT_UNPAIRABLE, "not_unpairable", m_PENT)
+DEF_TUNE (X86_TUNE_NOT_UNPAIRABLE, "not_unpairable", m_PENT | m_IAMCU)
/* X86_TUNE_PARTIAL_REG_STALL: Pentium pro, unlike later chips, handled
use of partial registers by renaming. This improved performance of 16bit
diff --git a/gcc/testsuite/gcc.target/i386/pr66749.c b/gcc/testsuite/gcc.target/i386/pr66749.c
new file mode 100644
index 0000000..affda08
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66749.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target ia32 } */
+/* { dg-require-effective-target nonpic } */
+/* { dg-options "-O2 -miamcu -mtune=iamcu" } */
+
+char a[10], b[10];
+
+int f(int i)
+{
+ return a[i+1] + b[i+1];
+}
+
+/* { dg-final { scan-assembler "a\\+1" } } */
+/* { dg-final { scan-assembler "b\\+1" } } */
--
2.4.3
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