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| author | Daniel Hellstrom <daniel@gaisler.com> | 2014-05-27 11:15:46 +0200 |
|---|---|---|
| committer | Daniel Hellstrom <daniel@gaisler.com> | 2014-12-02 13:55:50 +0100 |
| commit | 348d1812ba3bb83e2be6a99a7c706c5ea3a9d784 (patch) | |
| tree | 6df17a461ba98b846f1881c265fa7d286bfc32e9 | |
| parent | DEVFS04: make test work on LEON3-FT GR712RC (diff) | |
| download | rtems-348d1812ba3bb83e2be6a99a7c706c5ea3a9d784.tar.bz2 | |
SPARC: window overflow optimization
I see no need for waiting the 3 instruction delay for wim to be
written in this case, since the STD after does not depend on WIM
| -rw-r--r-- | c/src/lib/libbsp/sparc/shared/start/start.S | 11 | ||||
| -rw-r--r-- | c/src/lib/libcpu/sparc/reg_win/window.S | 25 |
2 files changed, 19 insertions, 17 deletions
diff --git a/c/src/lib/libbsp/sparc/shared/start/start.S b/c/src/lib/libbsp/sparc/shared/start/start.S index eb8e3c43a4..b7067b32bd 100644 --- a/c/src/lib/libbsp/sparc/shared/start/start.S +++ b/c/src/lib/libbsp/sparc/shared/start/start.S @@ -42,6 +42,15 @@ subcc %g1, 3, %g0; ! prepare for syscall 3 check /* + * Window Overflow optimized trap table entry + */ +#define WOTRAP(_vector, _handler) \ + sethi %hi(_handler), %l4; \ + jmp %l4+%lo(_handler); \ + save; \ + nop + +/* * Software trap. Treat as BAD_TRAP for the time being... */ @@ -72,7 +81,7 @@ SYM(trap_table): BAD_TRAP; ! 02 illegal instruction BAD_TRAP; ! 03 privileged instruction BAD_TRAP; ! 04 fp disabled - TRAP( 5, SYM(window_overflow_trap_handler) ); ! 05 window overflow + WOTRAP(5, SYM(window_overflow_trap_handler)); ! 05 window overflow TRAP( 6, SYM(window_underflow_trap_handler) );! 06 window underflow BAD_TRAP; ! 07 memory address not aligned BAD_TRAP; ! 08 fp exception diff --git a/c/src/lib/libcpu/sparc/reg_win/window.S b/c/src/lib/libcpu/sparc/reg_win/window.S index dffac6af92..535dc83105 100644 --- a/c/src/lib/libcpu/sparc/reg_win/window.S +++ b/c/src/lib/libcpu/sparc/reg_win/window.S @@ -29,9 +29,8 @@ * * On entry: * - * l0 = psr (from trap table) - * l1 = pc - * l2 = npc + * prev regwin l1 = pc + * prev regwin l2 = npc */ PUBLIC(window_overflow_trap_handler) @@ -51,29 +50,23 @@ SYM(window_overflow_trap_handler): * register will result in the local register set changing. */ - mov %wim, %l3 ! l3 = WIM - mov %g1, %l7 ! save g1 - srl %l3, 1, %g1 ! g1 = WIM >> 1 - sll %l3, SPARC_NUMBER_OF_REGISTER_WINDOWS-1 , %l4 - ! l4 = WIM << (Number Windows - 1) - or %l4, %g1, %g1 ! g1 = (WIM >> 1) | - ! (WIM << (Number Windows - 1)) - - save ! Get into window to be saved. - mov %g1, %wim ! load new WIM - nop; nop; nop ! 3 slot delay std %l0, [%sp + 0x00] ! save local register set std %l2, [%sp + 0x08] + mov %wim, %l3 + sll %l3, SPARC_NUMBER_OF_REGISTER_WINDOWS-1 , %l2 + ! l2 = WIM << (Number Windows - 1) std %l4, [%sp + 0x10] std %l6, [%sp + 0x18] + srl %l3, 1, %l3 ! l3 = WIM >> 1 + wr %l3, %l2, %wim ! WIM = (WIM >> 1) ^ + ! (WIM << (Number Windows - 1)) std %i0, [%sp + 0x20] ! save input register set std %i2, [%sp + 0x28] std %i4, [%sp + 0x30] std %i6, [%sp + 0x38] restore ! Go back to trap window. - mov %l7, %g1 ! restore g1 jmp %l1 ! Re-execute save. - rett %l2 + rett %l2 /* * Window underflow trap handler. |