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author | Andy Wingo <wingo@pobox.com> | 2015-09-22 10:24:30 +0000 |
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committer | Andy Wingo <wingo@pobox.com> | 2015-10-21 11:49:20 +0200 |
commit | 0007507340b10754cb307763cbc8eeb064853926 (patch) | |
tree | ffce65ab7dd195fa2f45360bef7d9db62760ce67 /libguile/frames.h | |
parent | d7199da8c9d287b9602e053d470d0a822b4f7cec (diff) | |
download | guile-0007507340b10754cb307763cbc8eeb064853926.tar.gz |
VM stack grows downward
Adapt VM stack to grow downward. This will make native compilation look
more like the VM code, as we will be able to use native CALL
instructions, taking proper advantage of the return address buffer.
* libguile/continuations.c (scm_i_continuation_to_frame): Record offsets
from stack top.
* libguile/control.c (scm_i_prompt_pop_abort_args_x): Adapt for reversed
order of arguments, and instead of relying on the abort to push on the
number of arguments, make the caller save the stack depth, which
allows us to compute the number of arguments ourselves.
(reify_partial_continuation, scm_c_abort): Adapt to reversed stack
order.
* libguile/dynstack.c (scm_dynstack_wind_prompt): Since we wind the
stack in a downward direction, subtract the reloc instead of adding
it.
* libguile/dynstack.h (SCM_F_DYNSTACK_PROMPT_ESCAPE_ONLY): Remove flag;
instead rely on prompt-establishing code to save the stack depth.
* libguile/eval.c (eval): Remove extraneous "volatile" declarations for
variables that are not re-set between the setjmp and any longjmp.
Adapt to save stack depth before instating the prompt.
* libguile/foreign.c (scm_i_foreign_call): Adapt to receive arguments in
reverse order.
* libguile/frames.c (frame_stack_top, scm_i_frame_stack_top): Adapt to
compute stack top instead of stack bottom.
(scm_c_frame_closure): Adapt to stack growth change.
(scm_frame_num_locals, scm_frame_local_ref, scm_frame_set_x): Use
union data type to access stack.
(RELOC): Reformat.
(scm_c_frame_previous): Adapt to stack growth change.
* libguile/frames.h: Adapt stack diagram to indicate that the stack
grows up.
(union scm_vm_stack_element): New data type used to access items on
the stack.
(SCM_FRAME_PREVIOUS_SP)
(SCM_FRAME_RETURN_ADDRESS, SCM_FRAME_SET_RETURN_ADDRESS)
(SCM_FRAME_DYNAMIC_LINK, SCM_FRAME_SET_DYNAMIC_LINK)
(SCM_FRAME_LOCAL, SCM_FRAME_NUM_LOCALS): Adapt to stack representation
change.
(SCM_FRAME_SLOT): New helper.
(SCM_VM_FRAME_FP, SCM_VM_FRAME_SP): Adapt to stack growth change.
* libguile/stacks.c (scm_make_stack): Record offsets from top of stack.
* libguile/throw.c (catch): Adapt to scm_i_prompt_pop_abort_args_x
change.
* libguile/vm-engine.c (ALLOC_FRAME, RESET_FRAME):
(FRAME_LOCALS_COUNT_FROM): Adapt to stack growth change.
(LOCAL_ADDRESS): Use SCM_FRAME_SLOT to get the address as the proper
data type.
(RETURN_ONE_VALUE, RETURN_VALUE_LIST): Adapt to stack growth change.
(apply): Shuffling up the SMOB apply args can cause the stack to
expand, so use ALLOC_FRAME instead of RESET_FRAME.
(vm_engine): Adapt for stack growth change.
* libguile/vm.c (vm_increase_sp, vm_push_sp, vm_restore_sp): Adapt to
stack representation change.
(scm_i_vm_cont_to_frame): Adapt to take offsets from the top.
(scm_i_vm_capture_stack): Adapt to capture from the top.
(vm_return_to_continuation_inner): Adapt for data type changes.
(vm_return_to_continuation): Likewise, and instead of looping, just
splat the saved arguments on with memcpy.
(vm_dispatch_hook): Adapt to receive arguments in the reverse order.
Adapt callers.
(vm_abort): There is never a tail argument. Adapt to stack
representation change.
(vm_reinstate_partial_continuation)
(vm_reinstate_partial_continuation_inner): Adapt to stack growth
change.
(allocate_stack, free_stack): Adapt to data type change.
(expand_stack): Don't try to mremap(), as you can't grow a mapping
from the bottom. Without knowing that there's a free mapping space
right below the old stack, which there usually isn't on Linux, we have
to copy. We can't use MAP_GROWSDOWN because Linux is buggy.
(make_vm): Adapt to stack representation changes.
(return_unused_stack_to_os): Round down instead of up, as the stack
grows down.
(scm_i_vm_mark_stack): Adapt to walk up the stack.
(scm_i_vm_free_stack): Adapt to scm_vm changes.
(vm_expand_stack_inner, reset_stack_limit, vm_expand_stack): Adapt to
the stack growing down.
(scm_call_n): Adapt to the stack growing down. Don't allow argv to
point into the stack.
* libguile/vm.h (struct scm_vm, struct scm_vm_cont): Adapt to hold the
stack top and bottom.
Diffstat (limited to 'libguile/frames.h')
-rw-r--r-- | libguile/frames.h | 76 |
1 files changed, 36 insertions, 40 deletions
diff --git a/libguile/frames.h b/libguile/frames.h index 31f86345f..c2f1e57db 100644 --- a/libguile/frames.h +++ b/libguile/frames.h @@ -1,4 +1,4 @@ -/* Copyright (C) 2001, 2009, 2010, 2011, 2012, 2013, 2014 Free Software Foundation, Inc. +/* Copyright (C) 2001, 2009, 2010, 2011, 2012, 2013, 2014, 2015 Free Software Foundation, Inc. * * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License @@ -38,24 +38,29 @@ Stack frame layout ------------------ - /------------------\ - | Local N-1 | <- sp | ... | - | Local 1 | - | Local 0 | <- fp = SCM_FRAME_LOCALS_ADDRESS (fp) - +==================+ + +==================+ <- fp + 2 = SCM_FRAME_PREVIOUS_SP (fp) + | Dynamic link | + +------------------+ | Return address | - | Dynamic link | <- fp - 2 = SCM_FRAME_LOWER_ADDRESS (fp) - +==================+ - | | <- fp - 3 = SCM_FRAME_PREVIOUS_SP (fp) + +==================+ <- fp + | Local 0 | + +------------------+ + | Local 1 | + +------------------+ + | ... | + +------------------+ + | Local N-1 | + \------------------/ <- sp + + The stack grows down. The calling convention is that a caller prepares a stack frame consisting of the saved FP and the return address, followed by the procedure and then the arguments to the call, in order. Thus in the beginning of a call, the procedure being called is in slot 0, the first argument is in slot 1, and the SP points to the last argument. - The number of arguments, including the procedure, is thus SP - FP + - 1. + The number of arguments, including the procedure, is thus FP - SP. After ensuring that the correct number of arguments have been passed, a function will set the stack pointer to point to the last local @@ -80,35 +85,26 @@ -/* This structure maps to the contents of a VM stack frame. It can - alias a frame directly. */ -struct scm_vm_frame +/* Each element on the stack occupies the same amount of space. */ +union scm_vm_stack_element { - SCM *dynamic_link; - scm_t_uint32 *return_address; - SCM locals[1]; /* Variable-length */ -}; - -#define SCM_FRAME_LOWER_ADDRESS(fp) (((SCM *) (fp)) - 2) -#define SCM_FRAME_STRUCT(fp) \ - ((struct scm_vm_frame *) SCM_FRAME_LOWER_ADDRESS (fp)) -#define SCM_FRAME_LOCALS_ADDRESS(fp) (SCM_FRAME_STRUCT (fp)->locals) - -#define SCM_FRAME_PREVIOUS_SP(fp) (((SCM *) (fp)) - 3) + union scm_vm_stack_element *fp; + scm_t_uint32 *ip; + SCM scm; -#define SCM_FRAME_RETURN_ADDRESS(fp) \ - (SCM_FRAME_STRUCT (fp)->return_address) -#define SCM_FRAME_SET_RETURN_ADDRESS(fp, ra) \ - SCM_FRAME_STRUCT (fp)->return_address = (ra) -#define SCM_FRAME_DYNAMIC_LINK(fp) \ - (SCM_FRAME_STRUCT (fp)->dynamic_link) -#define SCM_FRAME_SET_DYNAMIC_LINK(fp, dl) \ - SCM_FRAME_DYNAMIC_LINK (fp) = (dl) -#define SCM_FRAME_LOCAL(fp,i) \ - (SCM_FRAME_STRUCT (fp)->locals[i]) + /* For GC purposes. */ + void *ptr; + scm_t_bits bits; +}; -#define SCM_FRAME_NUM_LOCALS(fp, sp) \ - ((sp) + 1 - &SCM_FRAME_LOCAL (fp, 0)) +#define SCM_FRAME_PREVIOUS_SP(fp_) ((fp_) + 2) +#define SCM_FRAME_RETURN_ADDRESS(fp_) ((fp_)[0].ip) +#define SCM_FRAME_SET_RETURN_ADDRESS(fp_, ra) ((fp_)[0].ip = (ra)) +#define SCM_FRAME_DYNAMIC_LINK(fp_) ((fp_)[1].fp) +#define SCM_FRAME_SET_DYNAMIC_LINK(fp_, dl) ((fp_)[1].fp = (dl)) +#define SCM_FRAME_SLOT(fp_,i) ((fp_) - (i) - 1) +#define SCM_FRAME_LOCAL(fp_,i) (SCM_FRAME_SLOT (fp_, i)->scm) +#define SCM_FRAME_NUM_LOCALS(fp_, sp) ((fp_) - (sp)) /* @@ -137,13 +133,13 @@ enum scm_vm_frame_kind #define SCM_VM_FRAME_STACK_HOLDER(f) SCM_VM_FRAME_DATA (f)->stack_holder #define SCM_VM_FRAME_FP_OFFSET(f) SCM_VM_FRAME_DATA (f)->fp_offset #define SCM_VM_FRAME_SP_OFFSET(f) SCM_VM_FRAME_DATA (f)->sp_offset -#define SCM_VM_FRAME_FP(f) (SCM_VM_FRAME_FP_OFFSET (f) + scm_i_frame_stack_base (f)) -#define SCM_VM_FRAME_SP(f) (SCM_VM_FRAME_SP_OFFSET (f) + scm_i_frame_stack_base (f)) +#define SCM_VM_FRAME_FP(f) (scm_i_frame_stack_top (f) - SCM_VM_FRAME_FP_OFFSET (f)) +#define SCM_VM_FRAME_SP(f) (scm_i_frame_stack_top (f) - SCM_VM_FRAME_SP_OFFSET (f)) #define SCM_VM_FRAME_IP(f) SCM_VM_FRAME_DATA (f)->ip #define SCM_VM_FRAME_OFFSET(f) scm_i_frame_offset (f) #define SCM_VALIDATE_VM_FRAME(p,x) SCM_MAKE_VALIDATE (p, x, VM_FRAME_P) -SCM_INTERNAL SCM* scm_i_frame_stack_base (SCM frame); +SCM_INTERNAL union scm_vm_stack_element* scm_i_frame_stack_top (SCM frame); SCM_INTERNAL scm_t_ptrdiff scm_i_frame_offset (SCM frame); /* See notes in frames.c before using this. */ |