From 8b69c5a38006d30d001561d47f7ecbd9bd3ead78 Mon Sep 17 00:00:00 2001 From: Jozef Lawrynowicz Date: Thu, 16 Jul 2020 11:34:50 +0100 Subject: [PATCH 4/5] MSP430: Implement TARGET_INSN_COST The length of an insn can be used to calculate its cost, when optimizing for size. When optimizing for speed, this is a good estimate, since the cycle cost of an MSP430 instruction increases with its length. gcc/ChangeLog: * config/msp430/msp430.c (TARGET_INSN_COST): Define. (msp430_insn_cost): New function. * config/msp430/msp430.h (BRANCH_COST): Define. (LOGICAL_OP_NON_SHORT_CIRCUIT): Define. gcc/testsuite/ChangeLog: * gcc.target/msp430/rtx-cost-O3-default.c: New test. * gcc.target/msp430/rtx-cost-O3-f5series.c: New test. * gcc.target/msp430/rtx-cost-Os-default.c: New test. * gcc.target/msp430/rtx-cost-Os-f5series.c: New test. --- gcc/config/msp430/msp430.c | 25 ++++++++--- gcc/config/msp430/msp430.h | 8 ++++ .../gcc.target/msp430/rtx-cost-O3-default.c | 42 ++++++++++++++++++ .../gcc.target/msp430/rtx-cost-O3-f5series.c | 38 ++++++++++++++++ .../gcc.target/msp430/rtx-cost-Os-default.c | 43 +++++++++++++++++++ .../gcc.target/msp430/rtx-cost-Os-f5series.c | 38 ++++++++++++++++ 6 files changed, 189 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/gcc.target/msp430/rtx-cost-O3-default.c create mode 100644 gcc/testsuite/gcc.target/msp430/rtx-cost-O3-f5series.c create mode 100644 gcc/testsuite/gcc.target/msp430/rtx-cost-Os-default.c create mode 100644 gcc/testsuite/gcc.target/msp430/rtx-cost-Os-f5series.c diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c index b7daafcc11a..35ccd2817ca 100644 --- a/gcc/config/msp430/msp430.c +++ b/gcc/config/msp430/msp430.c @@ -1195,11 +1195,6 @@ msp430_memory_move_cost (machine_mode mode ATTRIBUTE_UNUSED, return 2 * cost; } -/* BRANCH_COST - Changing from the default of 1 doesn't affect code generation, presumably - because there are no conditional move insns - when a condition is involved, - the only option is to use a cbranch. */ - /* For X, which must be a MEM RTX, return TRUE if it is an indirect memory reference, @Rn or @Rn+. */ static bool @@ -1711,6 +1706,26 @@ msp430_rtx_costs (rtx x, return false; } } + +#undef TARGET_INSN_COST +#define TARGET_INSN_COST msp430_insn_cost + +static int +msp430_insn_cost (rtx_insn *insn, bool speed ATTRIBUTE_UNUSED) +{ + if (recog_memoized (insn) < 0) + return 0; + + /* The returned cost must be relative to COSTS_N_INSNS (1). An insn with a + length of 2 bytes is the smallest possible size and so must be equivalent + to COSTS_N_INSNS (1). */ + return COSTS_N_INSNS (get_attr_length (insn) / 2); + + /* FIXME Add more detailed costs when optimizing for speed. + For now the length of the instruction is a good approximiation and roughly + correlates with cycle cost. */ +} + /* Function Entry and Exit */ diff --git a/gcc/config/msp430/msp430.h b/gcc/config/msp430/msp430.h index b813e825311..830101408a5 100644 --- a/gcc/config/msp430/msp430.h +++ b/gcc/config/msp430/msp430.h @@ -245,6 +245,14 @@ extern const char *msp430_get_linker_devices_include_path (int, const char **); #define HAS_LONG_COND_BRANCH 0 #define HAS_LONG_UNCOND_BRANCH 0 +/* The cost of a branch sequence is roughly 3 "cheap" instructions. */ +#define BRANCH_COST(speed_p, predictable_p) 3 + +/* Override the default BRANCH_COST heuristic to indicate that it is preferable + to retain short-circuit operations, this results in significantly better + codesize and performance. */ +#define LOGICAL_OP_NON_SHORT_CIRCUIT 0 + #define LOAD_EXTEND_OP(M) ZERO_EXTEND #define WORD_REGISTER_OPERATIONS 1 diff --git a/gcc/testsuite/gcc.target/msp430/rtx-cost-O3-default.c b/gcc/testsuite/gcc.target/msp430/rtx-cost-O3-default.c new file mode 100644 index 00000000000..1bd6a142002 --- /dev/null +++ b/gcc/testsuite/gcc.target/msp430/rtx-cost-O3-default.c @@ -0,0 +1,42 @@ +/* { dg-do compile } */ +/* { dg-options "-O3" } */ +/* { dg-final { check-function-bodies "**" "" } } */ + +/* Verify the MSP430 cost model is working as expected for the default ISA + (msp430x) and hwmult (none), when compiling at -O3. */ + +char arr[2]; +char a; +char *ptr; + +/* +** foo: +** ... +** MOV.B \&a, \&arr\+1 +** MOV.* #arr\+2, \&ptr +** ... +*/ + +void +foo (void) +{ + arr[1] = a; + ptr = arr + 2; +} + +extern void ext (void); + +/* +** bar: +** ... +** CALL.* #ext +** CALL.* #ext +** ... +*/ + +void +bar (void) +{ + ext (); + ext (); +} diff --git a/gcc/testsuite/gcc.target/msp430/rtx-cost-O3-f5series.c b/gcc/testsuite/gcc.target/msp430/rtx-cost-O3-f5series.c new file mode 100644 index 00000000000..1e48625f2e5 --- /dev/null +++ b/gcc/testsuite/gcc.target/msp430/rtx-cost-O3-f5series.c @@ -0,0 +1,38 @@ +/* { dg-do compile } */ +/* { dg-options "-O3 -mhwmult=f5series" } */ +/* { dg-final { check-function-bodies "**" "" } } */ + +/* Verify the MSP430 cost model is working as expected for the default ISA + (msp430x) and f5series hwmult, when compiling at -O3. */ + +volatile unsigned long a; +volatile unsigned int b; +volatile unsigned long c; +unsigned long res1; +unsigned long res2; +unsigned long res3; + +/* +** foo: +** ... +** MOV.B #16, R14 +** CALL.* #__mspabi_slll +** ... +** MOV.* \&res2.* +** ... +** RLA.*RLC.* +** ... +** MOV.* \&res3.* +** ... +** RLA.*RLC.* +** ... +*/ +void foo (void) +{ + /* Use the shift library function for this. */ + res1 = (a << 16) | b; + /* Emit 7 inline shifts for this. */ + res2 *= 128; + /* Perform this multiplication inline, using addition and shifts. */ + res3 *= 100; +} diff --git a/gcc/testsuite/gcc.target/msp430/rtx-cost-Os-default.c b/gcc/testsuite/gcc.target/msp430/rtx-cost-Os-default.c new file mode 100644 index 00000000000..8f3d1b28049 --- /dev/null +++ b/gcc/testsuite/gcc.target/msp430/rtx-cost-Os-default.c @@ -0,0 +1,43 @@ +/* { dg-do compile } */ +/* { dg-options "-Os" } */ +/* { dg-final { check-function-bodies "**" "" } } */ + +/* Verify the MSP430 cost model is working as expected for the default ISA + (msp430x) and hwmult (none), when compiling at -Os. */ + +char arr[2]; +char a; +char *ptr; + +/* +** foo: +** ... +** MOV.B \&a, \&arr\+1 +** MOV.* #arr\+2, \&ptr +** ... +*/ + +void +foo (void) +{ + arr[1] = a; + ptr = arr + 2; +} + +extern void ext (void); + +/* +** bar: +** ... +** MOV.* #ext, R10 +** CALL.* R10 +** CALL.* R10 +** ... +*/ + +void +bar (void) +{ + ext (); + ext (); +} diff --git a/gcc/testsuite/gcc.target/msp430/rtx-cost-Os-f5series.c b/gcc/testsuite/gcc.target/msp430/rtx-cost-Os-f5series.c new file mode 100644 index 00000000000..bb37f9083d9 --- /dev/null +++ b/gcc/testsuite/gcc.target/msp430/rtx-cost-Os-f5series.c @@ -0,0 +1,38 @@ +/* { dg-do compile } */ +/* { dg-options "-Os -mhwmult=f5series" } */ +/* { dg-final { check-function-bodies "**" "" } } */ + +/* Verify the MSP430 cost model is working as expected for the default ISA + (msp430x) and f5series hwmult, when compiling at -Os. */ + +volatile unsigned long a; +volatile unsigned int b; +volatile unsigned long c; +unsigned long res1; +unsigned long res2; +unsigned long res3; + +/* +** foo: +** ... +** MOV.B #16, R14 +** CALL.* #__mspabi_slll +** ... +** MOV.B #7, R14 +** CALL.* #__mspabi_slll +** ... +** MOV.B #100, R14 +** MOV.B #0, R15 +** ... +** CALL.* #__mulsi2_f5 +** ... +*/ +void foo (void) +{ + /* Use the shift library function for this. */ + res1 = (a << 16) | b; + /* Likewise. */ + res2 *= 128; + /* Use the hardware multiply library function for this. */ + res3 *= 100; +} -- 2.27.0