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authorAndy Wingo <wingo@pobox.com>2018-07-19 10:56:44 +0200
committerAndy Wingo <wingo@pobox.com>2018-07-20 11:42:30 +0200
commitc2a8224a63da432c82f24a76c008e4cfe9cba25b (patch)
tree76416a0cb8f23953912b4ac8ce5c691f6e4a8635 /libguile/vm-engine.c
parent043432fd573648fe8591672aca7e2438b71e6774 (diff)
downloadguile-c2a8224a63da432c82f24a76c008e4cfe9cba25b.tar.gz
Rework VM approach to shuffling unknown numbers of args
* libguile/vm-engine.c (shuffle-down, expand-apply-argument): New instructions. (tail-call, tail-call-label, return-values): Don't reset the frame. The compiler should reset the frame appropriately. (tail-call/shuffle, tail-apply): Remove unused instructions. * libguile/vm.c (vm_builtin_apply_code): Use new shuffle-down and expand-apply-argument opcodes. (vm_builtin_call_with_values_code): Replace tail-call/shuffle with shuffle-down then tail-call. * libguile/jit.c (compile_shuffle_down, compile_expand_apply_argument): Add compiler stubs (COMPILE_X8_F12_F12): New definition. (compile_tail_call_shuffle, compile_tail_apply): Remove unused compilers. * module/language/cps/compile-bytecode.scm (compile-function): Emit reset-frame before tail calls and returns. * module/system/vm/assembler.scm (system): Remove unbound "emit-return" export. * module/system/vm/disassembler.scm (code-annotation) (instruction-has-fallthrough?, define-stack-effect-parser): Adapt for opcode changes.
Diffstat (limited to 'libguile/vm-engine.c')
-rw-r--r--libguile/vm-engine.c171
1 files changed, 59 insertions, 112 deletions
diff --git a/libguile/vm-engine.c b/libguile/vm-engine.c
index 341a006fd..383b4f5df 100644
--- a/libguile/vm-engine.c
+++ b/libguile/vm-engine.c
@@ -428,20 +428,14 @@ VM_NAME (scm_thread *thread)
NEXT (0);
}
- /* tail-call nlocals:24
+ /* tail-call _:24
*
- * Tail-call a procedure. Requires that the procedure and all of the
- * arguments have already been shuffled into position. Will reset the
- * frame to NLOCALS.
+ * Tail-call the procedure in slot 0 with the arguments in the current
+ * stack frame. Requires that the procedure and all of the arguments
+ * have already been shuffled into position.
*/
- VM_DEFINE_OP (3, tail_call, "tail-call", OP1 (X8_C24))
+ VM_DEFINE_OP (3, tail_call, "tail-call", OP1 (X32))
{
- uint32_t nlocals;
-
- UNPACK_24 (op, nlocals);
-
- RESET_FRAME (nlocals);
-
if (SCM_LIKELY (SCM_PROGRAM_P (FP_REF (0))))
ip = SCM_PROGRAM_CODE (FP_REF (0));
else
@@ -456,21 +450,17 @@ VM_NAME (scm_thread *thread)
NEXT (0);
}
- /* tail-call-label nlocals:24 label:32
+ /* tail-call-label _:24 label:32
*
* Tail-call a known procedure. As call is to call-label, tail-call
* is to tail-call-label.
*/
- VM_DEFINE_OP (4, tail_call_label, "tail-call-label", OP2 (X8_C24, L32))
+ VM_DEFINE_OP (4, tail_call_label, "tail-call-label", OP2 (X32, L32))
{
- uint32_t nlocals;
int32_t label;
- UNPACK_24 (op, nlocals);
label = ip[1];
- RESET_FRAME (nlocals);
-
ip += label;
APPLY_HOOK ();
@@ -478,39 +468,10 @@ VM_NAME (scm_thread *thread)
NEXT (0);
}
- /* tail-call/shuffle from:24
- *
- * Tail-call a procedure. The procedure should already be set to slot
- * 0. The rest of the args are taken from the frame, starting at
- * FROM, shuffled down to start at slot 0. This is part of the
- * implementation of the call-with-values builtin.
- */
- VM_DEFINE_OP (5, tail_call_shuffle, "tail-call/shuffle", OP1 (X8_F24))
+ VM_DEFINE_OP (5, unused_5, NULL, NOP)
{
- uint32_t n, from, nlocals;
-
- UNPACK_24 (op, from);
-
- VM_ASSERT (from > 0, abort ());
- nlocals = FRAME_LOCALS_COUNT ();
-
- for (n = 0; from + n < nlocals; n++)
- FP_SET (n + 1, FP_REF (from + n));
-
- RESET_FRAME (n + 1);
-
- if (SCM_LIKELY (SCM_PROGRAM_P (FP_REF (0))))
- ip = SCM_PROGRAM_CODE (FP_REF (0));
- else
- {
- SYNC_IP ();
- CALL_INTRINSIC (apply_non_program, (thread));
- CACHE_REGISTER ();
- }
-
- APPLY_HOOK ();
-
- NEXT (0);
+ vm_error_bad_instruction (op);
+ abort (); /* never reached */
}
/* receive dst:12 proc:12 _:8 nlocals:24
@@ -554,29 +515,36 @@ VM_NAME (scm_thread *thread)
NEXT (2);
}
- VM_DEFINE_OP (8, unused_8, NULL, NOP)
+ /* shuffle-down from:12 to:12
+ *
+ * Shuffle down values from FROM to TO, reducing the frame size by
+ * (FROM-TO) slots. Part of the internal implementation of
+ * call-with-values, values, and apply.
+ */
+ VM_DEFINE_OP (8, shuffle_down, "shuffle-down", OP1 (X8_F12_F12))
{
- vm_error_bad_instruction (op);
- abort (); /* never reached */
+ uint32_t n, from, to, nlocals;
+
+ UNPACK_12_12 (op, from, to);
+
+ VM_ASSERT (from > to, abort ());
+ nlocals = FRAME_LOCALS_COUNT ();
+
+ for (n = 0; from + n < nlocals; n++)
+ FP_SET (to + n, FP_REF (from + n));
+
+ RESET_FRAME (to + n);
+
+ NEXT (1);
}
- /* return-values nlocals:24
+ /* return-values _:24
*
- * Return a number of values from a call frame. This opcode
- * corresponds to an application of `values' in tail position. As
- * with tail calls, we expect that the values have already been
- * shuffled down to a contiguous array starting at slot 1.
- * If NLOCALS is not zero, we also reset the frame to hold NLOCALS
- * values.
+ * Return all values from a call frame.
*/
- VM_DEFINE_OP (9, return_values, "return-values", OP1 (X8_C24))
+ VM_DEFINE_OP (9, return_values, "return-values", OP1 (X32))
{
union scm_vm_stack_element *old_fp;
- uint32_t nlocals;
-
- UNPACK_24 (op, nlocals);
- if (nlocals)
- RESET_FRAME (nlocals);
old_fp = VP->fp;
ip = SCM_FRAME_VIRTUAL_RETURN_ADDRESS (VP->fp);
@@ -706,51 +674,10 @@ VM_NAME (scm_thread *thread)
NEXT (0);
}
- /* tail-apply _:24
- *
- * Tail-apply the procedure in local slot 1 to the rest of the
- * arguments. This instruction is part of the implementation of
- * `apply', and is not generated by the compiler.
- */
- VM_DEFINE_OP (14, tail_apply, "tail-apply", OP1 (X32))
+ VM_DEFINE_OP (14, unused_14, NULL, NOP)
{
- int i, list_idx, list_len, nlocals;
- SCM list;
-
- nlocals = FRAME_LOCALS_COUNT ();
- // At a minimum, there should be apply, f, and the list.
- VM_ASSERT (nlocals >= 3, abort ());
- list_idx = nlocals - 1;
- list = FP_REF (list_idx);
-
- SYNC_IP ();
- list_len = CALL_INTRINSIC (rest_arg_length, (list));
-
- nlocals = nlocals - 2 + list_len;
- ALLOC_FRAME (nlocals);
-
- for (i = 1; i < list_idx; i++)
- FP_SET (i - 1, FP_REF (i));
-
- /* Null out these slots, just in case there are less than 2 elements
- in the list. */
- FP_SET (list_idx - 1, SCM_UNDEFINED);
- FP_SET (list_idx, SCM_UNDEFINED);
-
- for (i = 0; i < list_len; i++, list = SCM_CDR (list))
- FP_SET (list_idx - 1 + i, SCM_CAR (list));
-
- if (SCM_LIKELY (SCM_PROGRAM_P (FP_REF (0))))
- ip = SCM_PROGRAM_CODE (FP_REF (0));
- else
- {
- CALL_INTRINSIC (apply_non_program, (thread));
- CACHE_REGISTER ();
- }
-
- APPLY_HOOK ();
-
- NEXT (0);
+ vm_error_bad_instruction (op);
+ abort (); /* never reached */
}
/* call/cc _:24
@@ -1042,10 +969,30 @@ VM_NAME (scm_thread *thread)
NEXT (1);
}
- VM_DEFINE_OP (30, unused_30, NULL, NOP)
+ /* expand-apply-argument _:24
+ *
+ * Take the last local in a frame and expand it out onto the stack, as
+ * for the last argument to "apply".
+ */
+ VM_DEFINE_OP (30, expand_apply_argument, "expand-apply-argument", OP1 (X32))
{
- vm_error_bad_instruction (op);
- abort ();
+ int list_len;
+ SCM list;
+
+ list = SP_REF (0);
+
+ SYNC_IP ();
+ list_len = CALL_INTRINSIC (rest_arg_length, (list));
+
+ ALLOC_FRAME (FRAME_LOCALS_COUNT () - 1 + list_len);
+
+ while (list_len--)
+ {
+ SP_SET (list_len, SCM_CAR (list));
+ list = SCM_CDR (list);
+ }
+
+ NEXT (1);
}
/* bind-kwargs nreq:24 flags:8 nreq-and-opt:24 _:8 ntotal:24 kw-offset:32