Message ID | 1394851732-25692-12-git-send-email-rth@twiddle.net |
---|---|
State | New |
Headers | show |
On 15.03.2014 03:48, Richard Henderson wrote: > We don't need the FP within translated code, and the LR is > otherwise unused. > > Signed-off-by: Richard Henderson <rth@twiddle.net> The downside of this is that it disregards the procedure call standard from ARM. Peter what do you think about this? > --- > tcg/aarch64/tcg-target.c | 44 ++++++++++++++++---------------------------- > tcg/aarch64/tcg-target.h | 32 +++++++++++++++++--------------- > 2 files changed, 33 insertions(+), 43 deletions(-) > > diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c > index 0d6d495..2e70810 100644 > --- a/tcg/aarch64/tcg-target.c > +++ b/tcg/aarch64/tcg-target.c > @@ -23,10 +23,7 @@ static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = { > "%x0", "%x1", "%x2", "%x3", "%x4", "%x5", "%x6", "%x7", > "%x8", "%x9", "%x10", "%x11", "%x12", "%x13", "%x14", "%x15", > "%x16", "%x17", "%x18", "%x19", "%x20", "%x21", "%x22", "%x23", > - "%x24", "%x25", "%x26", "%x27", "%x28", > - "%fp", /* frame pointer */ > - "%lr", /* link register */ > - "%sp", /* stack pointer */ > + "%x24", "%x25", "%x26", "%x27", "%x28", "%x29", "%x30", "%sp", > }; > #endif /* NDEBUG */ > > @@ -39,18 +36,19 @@ static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = { > static const int tcg_target_reg_alloc_order[] = { > TCG_REG_X20, TCG_REG_X21, TCG_REG_X22, TCG_REG_X23, > TCG_REG_X24, TCG_REG_X25, TCG_REG_X26, TCG_REG_X27, > - TCG_REG_X28, /* we will reserve this for GUEST_BASE if configured */ > + TCG_REG_X28, > + TCG_REG_X29, /* maybe used for TCG_REG_GUEST_BASE */ > > - TCG_REG_X9, TCG_REG_X10, TCG_REG_X11, TCG_REG_X12, > - TCG_REG_X13, TCG_REG_X14, TCG_REG_X15, > + TCG_REG_X8, TCG_REG_X9, TCG_REG_X10, TCG_REG_X11, > + TCG_REG_X12, TCG_REG_X13, TCG_REG_X14, TCG_REG_X15, > TCG_REG_X16, TCG_REG_X17, > > - TCG_REG_X18, TCG_REG_X19, /* will not use these, see tcg_target_init */ > - > TCG_REG_X0, TCG_REG_X1, TCG_REG_X2, TCG_REG_X3, > TCG_REG_X4, TCG_REG_X5, TCG_REG_X6, TCG_REG_X7, > > - TCG_REG_X8, /* will not use, see tcg_target_init */ > + /* X18 reserved by system */ > + /* X19 reserved for AREG0 */ > + /* X30 reserved as temporary */ > }; > > static const int tcg_target_call_iarg_regs[8] = { > @@ -61,13 +59,13 @@ static const int tcg_target_call_oarg_regs[1] = { > TCG_REG_X0 > }; > > -#define TCG_REG_TMP TCG_REG_X8 > +#define TCG_REG_TMP TCG_REG_X30 > > #ifndef CONFIG_SOFTMMU > -# if defined(CONFIG_USE_GUEST_BASE) > -# define TCG_REG_GUEST_BASE TCG_REG_X28 > +# ifdef CONFIG_USE_GUEST_BASE > +# define TCG_REG_GUEST_BASE TCG_REG_X29 > # else > -# define TCG_REG_GUEST_BASE TCG_REG_XZR > +# define TCG_REG_GUEST_BASE TCG_REG_XZR > # endif > #endif > > @@ -569,12 +567,6 @@ static void tcg_out_movr(TCGContext *s, TCGType ext, TCGReg rd, TCGReg rm) > tcg_out_insn(s, 3510, ORR, ext, rd, TCG_REG_XZR, rm); > } > > -/* Register to register move using ADDI (move to/from SP). */ > -static void tcg_out_movr_sp(TCGContext *s, TCGType ext, TCGReg rd, TCGReg rn) > -{ > - tcg_out_insn(s, 3401, ADDI, ext, rd, rn, 0); > -} > - > /* This function is used for the Logical (immediate) instruction group. > The value of LIMM must satisfy IS_LIMM. See the comment above about > only supporting simplified logical immediates. */ > @@ -1868,11 +1860,10 @@ static void tcg_target_init(TCGContext *s) > (1 << TCG_REG_X12) | (1 << TCG_REG_X13) | > (1 << TCG_REG_X14) | (1 << TCG_REG_X15) | > (1 << TCG_REG_X16) | (1 << TCG_REG_X17) | > - (1 << TCG_REG_X18)); > + (1 << TCG_REG_X18) | (1 << TCG_REG_X30)); > > tcg_regset_clear(s->reserved_regs); > tcg_regset_set_reg(s->reserved_regs, TCG_REG_SP); > - tcg_regset_set_reg(s->reserved_regs, TCG_REG_FP); > tcg_regset_set_reg(s->reserved_regs, TCG_REG_TMP); > tcg_regset_set_reg(s->reserved_regs, TCG_REG_X18); /* platform register */ > > @@ -1899,13 +1890,10 @@ static void tcg_target_qemu_prologue(TCGContext *s) > tcg_out_push_pair(s, TCG_REG_SP, > TCG_REG_FP, TCG_REG_LR, frame_size_callee_saved); > > - /* FP -> callee_saved */ > - tcg_out_movr_sp(s, 1, TCG_REG_FP, TCG_REG_SP); > - > - /* store callee-preserved regs x19..x28 using FP -> callee_saved */ > + /* Store callee-preserved regs x19..x28. */ > for (r = TCG_REG_X19; r <= TCG_REG_X27; r += 2) { > int idx = (r - TCG_REG_X19) / 2 + 1; > - tcg_out_store_pair(s, TCG_REG_FP, r, r + 1, idx); > + tcg_out_store_pair(s, TCG_REG_SP, r, r + 1, idx); > } > > /* Make stack space for TCG locals. */ > @@ -1936,7 +1924,7 @@ static void tcg_target_qemu_prologue(TCGContext *s) > FP must be preserved, so it still points to callee_saved area */ > for (r = TCG_REG_X19; r <= TCG_REG_X27; r += 2) { > int idx = (r - TCG_REG_X19) / 2 + 1; > - tcg_out_load_pair(s, TCG_REG_FP, r, r + 1, idx); > + tcg_out_load_pair(s, TCG_REG_SP, r, r + 1, idx); > } > > /* pop (FP, LR), restore SP to previous frame, return */ > diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h > index 988983e..faccc36 100644 > --- a/tcg/aarch64/tcg-target.h > +++ b/tcg/aarch64/tcg-target.h > @@ -17,17 +17,23 @@ > #undef TCG_TARGET_STACK_GROWSUP > > typedef enum { > - TCG_REG_X0, TCG_REG_X1, TCG_REG_X2, TCG_REG_X3, TCG_REG_X4, > - TCG_REG_X5, TCG_REG_X6, TCG_REG_X7, TCG_REG_X8, TCG_REG_X9, > - TCG_REG_X10, TCG_REG_X11, TCG_REG_X12, TCG_REG_X13, TCG_REG_X14, > - TCG_REG_X15, TCG_REG_X16, TCG_REG_X17, TCG_REG_X18, TCG_REG_X19, > - TCG_REG_X20, TCG_REG_X21, TCG_REG_X22, TCG_REG_X23, TCG_REG_X24, > - TCG_REG_X25, TCG_REG_X26, TCG_REG_X27, TCG_REG_X28, > - TCG_REG_FP, /* frame pointer */ > - TCG_REG_LR, /* link register */ > - TCG_REG_SP, /* stack pointer or zero register */ > - TCG_REG_XZR = TCG_REG_SP /* same register number */ > - /* program counter is not directly accessible! */ > + TCG_REG_X0, TCG_REG_X1, TCG_REG_X2, TCG_REG_X3, > + TCG_REG_X4, TCG_REG_X5, TCG_REG_X6, TCG_REG_X7, > + TCG_REG_X8, TCG_REG_X9, TCG_REG_X10, TCG_REG_X11, > + TCG_REG_X12, TCG_REG_X13, TCG_REG_X14, TCG_REG_X15, > + TCG_REG_X16, TCG_REG_X17, TCG_REG_X18, TCG_REG_X19, > + TCG_REG_X20, TCG_REG_X21, TCG_REG_X22, TCG_REG_X23, > + TCG_REG_X24, TCG_REG_X25, TCG_REG_X26, TCG_REG_X27, > + TCG_REG_X28, TCG_REG_X29, TCG_REG_X30, > + > + /* X31 is either the stack pointer or zero, depending on context. */ > + TCG_REG_SP = 31, > + TCG_REG_XZR = 31, > + > + /* Aliases. */ > + TCG_REG_FP = TCG_REG_X29, > + TCG_REG_LR = TCG_REG_X30, > + TCG_AREG0 = TCG_REG_X19, > } TCGReg; > > #define TCG_TARGET_NB_REGS 32 > @@ -92,10 +98,6 @@ typedef enum { > #define TCG_TARGET_HAS_muluh_i64 1 > #define TCG_TARGET_HAS_mulsh_i64 1 > > -enum { > - TCG_AREG0 = TCG_REG_X19, > -}; > - > #define TCG_TARGET_HAS_new_ldst 0 > > static inline void flush_icache_range(uintptr_t start, uintptr_t stop) >
On 03/28/2014 02:48 AM, Claudio Fontana wrote: > On 15.03.2014 03:48, Richard Henderson wrote: >> We don't need the FP within translated code, and the LR is >> otherwise unused. >> >> Signed-off-by: Richard Henderson <rth@twiddle.net> > > The downside of this is that it disregards the procedure call standard from ARM. In what way do you believe the call standard to require a frame pointer? Certainly GCC avoids generating one when it isn't needed, so why should we? In any case, the real help comes in patch 14/26 where I implement the jit hook so that GDB can unwind through the code_gen_buffer. r~
diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c index 0d6d495..2e70810 100644 --- a/tcg/aarch64/tcg-target.c +++ b/tcg/aarch64/tcg-target.c @@ -23,10 +23,7 @@ static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = { "%x0", "%x1", "%x2", "%x3", "%x4", "%x5", "%x6", "%x7", "%x8", "%x9", "%x10", "%x11", "%x12", "%x13", "%x14", "%x15", "%x16", "%x17", "%x18", "%x19", "%x20", "%x21", "%x22", "%x23", - "%x24", "%x25", "%x26", "%x27", "%x28", - "%fp", /* frame pointer */ - "%lr", /* link register */ - "%sp", /* stack pointer */ + "%x24", "%x25", "%x26", "%x27", "%x28", "%x29", "%x30", "%sp", }; #endif /* NDEBUG */ @@ -39,18 +36,19 @@ static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = { static const int tcg_target_reg_alloc_order[] = { TCG_REG_X20, TCG_REG_X21, TCG_REG_X22, TCG_REG_X23, TCG_REG_X24, TCG_REG_X25, TCG_REG_X26, TCG_REG_X27, - TCG_REG_X28, /* we will reserve this for GUEST_BASE if configured */ + TCG_REG_X28, + TCG_REG_X29, /* maybe used for TCG_REG_GUEST_BASE */ - TCG_REG_X9, TCG_REG_X10, TCG_REG_X11, TCG_REG_X12, - TCG_REG_X13, TCG_REG_X14, TCG_REG_X15, + TCG_REG_X8, TCG_REG_X9, TCG_REG_X10, TCG_REG_X11, + TCG_REG_X12, TCG_REG_X13, TCG_REG_X14, TCG_REG_X15, TCG_REG_X16, TCG_REG_X17, - TCG_REG_X18, TCG_REG_X19, /* will not use these, see tcg_target_init */ - TCG_REG_X0, TCG_REG_X1, TCG_REG_X2, TCG_REG_X3, TCG_REG_X4, TCG_REG_X5, TCG_REG_X6, TCG_REG_X7, - TCG_REG_X8, /* will not use, see tcg_target_init */ + /* X18 reserved by system */ + /* X19 reserved for AREG0 */ + /* X30 reserved as temporary */ }; static const int tcg_target_call_iarg_regs[8] = { @@ -61,13 +59,13 @@ static const int tcg_target_call_oarg_regs[1] = { TCG_REG_X0 }; -#define TCG_REG_TMP TCG_REG_X8 +#define TCG_REG_TMP TCG_REG_X30 #ifndef CONFIG_SOFTMMU -# if defined(CONFIG_USE_GUEST_BASE) -# define TCG_REG_GUEST_BASE TCG_REG_X28 +# ifdef CONFIG_USE_GUEST_BASE +# define TCG_REG_GUEST_BASE TCG_REG_X29 # else -# define TCG_REG_GUEST_BASE TCG_REG_XZR +# define TCG_REG_GUEST_BASE TCG_REG_XZR # endif #endif @@ -569,12 +567,6 @@ static void tcg_out_movr(TCGContext *s, TCGType ext, TCGReg rd, TCGReg rm) tcg_out_insn(s, 3510, ORR, ext, rd, TCG_REG_XZR, rm); } -/* Register to register move using ADDI (move to/from SP). */ -static void tcg_out_movr_sp(TCGContext *s, TCGType ext, TCGReg rd, TCGReg rn) -{ - tcg_out_insn(s, 3401, ADDI, ext, rd, rn, 0); -} - /* This function is used for the Logical (immediate) instruction group. The value of LIMM must satisfy IS_LIMM. See the comment above about only supporting simplified logical immediates. */ @@ -1868,11 +1860,10 @@ static void tcg_target_init(TCGContext *s) (1 << TCG_REG_X12) | (1 << TCG_REG_X13) | (1 << TCG_REG_X14) | (1 << TCG_REG_X15) | (1 << TCG_REG_X16) | (1 << TCG_REG_X17) | - (1 << TCG_REG_X18)); + (1 << TCG_REG_X18) | (1 << TCG_REG_X30)); tcg_regset_clear(s->reserved_regs); tcg_regset_set_reg(s->reserved_regs, TCG_REG_SP); - tcg_regset_set_reg(s->reserved_regs, TCG_REG_FP); tcg_regset_set_reg(s->reserved_regs, TCG_REG_TMP); tcg_regset_set_reg(s->reserved_regs, TCG_REG_X18); /* platform register */ @@ -1899,13 +1890,10 @@ static void tcg_target_qemu_prologue(TCGContext *s) tcg_out_push_pair(s, TCG_REG_SP, TCG_REG_FP, TCG_REG_LR, frame_size_callee_saved); - /* FP -> callee_saved */ - tcg_out_movr_sp(s, 1, TCG_REG_FP, TCG_REG_SP); - - /* store callee-preserved regs x19..x28 using FP -> callee_saved */ + /* Store callee-preserved regs x19..x28. */ for (r = TCG_REG_X19; r <= TCG_REG_X27; r += 2) { int idx = (r - TCG_REG_X19) / 2 + 1; - tcg_out_store_pair(s, TCG_REG_FP, r, r + 1, idx); + tcg_out_store_pair(s, TCG_REG_SP, r, r + 1, idx); } /* Make stack space for TCG locals. */ @@ -1936,7 +1924,7 @@ static void tcg_target_qemu_prologue(TCGContext *s) FP must be preserved, so it still points to callee_saved area */ for (r = TCG_REG_X19; r <= TCG_REG_X27; r += 2) { int idx = (r - TCG_REG_X19) / 2 + 1; - tcg_out_load_pair(s, TCG_REG_FP, r, r + 1, idx); + tcg_out_load_pair(s, TCG_REG_SP, r, r + 1, idx); } /* pop (FP, LR), restore SP to previous frame, return */ diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h index 988983e..faccc36 100644 --- a/tcg/aarch64/tcg-target.h +++ b/tcg/aarch64/tcg-target.h @@ -17,17 +17,23 @@ #undef TCG_TARGET_STACK_GROWSUP typedef enum { - TCG_REG_X0, TCG_REG_X1, TCG_REG_X2, TCG_REG_X3, TCG_REG_X4, - TCG_REG_X5, TCG_REG_X6, TCG_REG_X7, TCG_REG_X8, TCG_REG_X9, - TCG_REG_X10, TCG_REG_X11, TCG_REG_X12, TCG_REG_X13, TCG_REG_X14, - TCG_REG_X15, TCG_REG_X16, TCG_REG_X17, TCG_REG_X18, TCG_REG_X19, - TCG_REG_X20, TCG_REG_X21, TCG_REG_X22, TCG_REG_X23, TCG_REG_X24, - TCG_REG_X25, TCG_REG_X26, TCG_REG_X27, TCG_REG_X28, - TCG_REG_FP, /* frame pointer */ - TCG_REG_LR, /* link register */ - TCG_REG_SP, /* stack pointer or zero register */ - TCG_REG_XZR = TCG_REG_SP /* same register number */ - /* program counter is not directly accessible! */ + TCG_REG_X0, TCG_REG_X1, TCG_REG_X2, TCG_REG_X3, + TCG_REG_X4, TCG_REG_X5, TCG_REG_X6, TCG_REG_X7, + TCG_REG_X8, TCG_REG_X9, TCG_REG_X10, TCG_REG_X11, + TCG_REG_X12, TCG_REG_X13, TCG_REG_X14, TCG_REG_X15, + TCG_REG_X16, TCG_REG_X17, TCG_REG_X18, TCG_REG_X19, + TCG_REG_X20, TCG_REG_X21, TCG_REG_X22, TCG_REG_X23, + TCG_REG_X24, TCG_REG_X25, TCG_REG_X26, TCG_REG_X27, + TCG_REG_X28, TCG_REG_X29, TCG_REG_X30, + + /* X31 is either the stack pointer or zero, depending on context. */ + TCG_REG_SP = 31, + TCG_REG_XZR = 31, + + /* Aliases. */ + TCG_REG_FP = TCG_REG_X29, + TCG_REG_LR = TCG_REG_X30, + TCG_AREG0 = TCG_REG_X19, } TCGReg; #define TCG_TARGET_NB_REGS 32 @@ -92,10 +98,6 @@ typedef enum { #define TCG_TARGET_HAS_muluh_i64 1 #define TCG_TARGET_HAS_mulsh_i64 1 -enum { - TCG_AREG0 = TCG_REG_X19, -}; - #define TCG_TARGET_HAS_new_ldst 0 static inline void flush_icache_range(uintptr_t start, uintptr_t stop)
We don't need the FP within translated code, and the LR is otherwise unused. Signed-off-by: Richard Henderson <rth@twiddle.net> --- tcg/aarch64/tcg-target.c | 44 ++++++++++++++++---------------------------- tcg/aarch64/tcg-target.h | 32 +++++++++++++++++--------------- 2 files changed, 33 insertions(+), 43 deletions(-)