diff options
author | Andy Wingo <wingo@pobox.com> | 2009-09-17 14:58:31 +0200 |
---|---|---|
committer | Andy Wingo <wingo@pobox.com> | 2009-10-16 15:56:11 +0200 |
commit | 97fcf583b7239ea17dbb73eae9438d21136eb2db (patch) | |
tree | f92ae6b6b840255fe58289b9ed3824aac3cbd0c5 | |
parent | f95f82f8e183f2744740bdc950dba9c856e09094 (diff) | |
download | guile-97fcf583b7239ea17dbb73eae9438d21136eb2db.tar.gz |
jumps encoded using 24 bits, not 19; blocks no longer aligned
* libguile/_scm.h (SCM_OBJCODE_MINOR_VERSION): Bump.
* libguile/vm-i-system.c (FETCH_OFFSET, BR): Labels are no longer 8-byte
aligned; instead, jumps are encoded into 3 bytes instead of 2.
(br, br-if, br-if-not, br-if-eq, br-if-not-eq, br-if-null)
(br-if-not-null, mv-call): Adapt for new length of br instructions (3
bytes instead of 2).
* libguile/vm.c (really_make_boot_program): Adapt hand-coded bytecode
for new offset regime.
* module/language/assembly.scm (align-block): No alignment necessary.
* module/language/assembly/compile-bytecode.scm (write-bytecode): Write
out breaks as 24-bit relative jumps.
* module/language/assembly/decompile-bytecode.scm (decode-load-program):
Decompile break instructions.
-rw-r--r-- | libguile/_scm.h | 2 | ||||
-rw-r--r-- | libguile/vm-i-system.c | 37 | ||||
-rw-r--r-- | libguile/vm.c | 5 | ||||
-rw-r--r-- | module/language/assembly.scm | 2 | ||||
-rw-r--r-- | module/language/assembly/compile-bytecode.scm | 14 | ||||
-rw-r--r-- | module/language/assembly/decompile-bytecode.scm | 19 |
6 files changed, 40 insertions, 39 deletions
diff --git a/libguile/_scm.h b/libguile/_scm.h index 8a9a21161..6aedebe72 100644 --- a/libguile/_scm.h +++ b/libguile/_scm.h @@ -172,7 +172,7 @@ /* Major and minor versions must be single characters. */ #define SCM_OBJCODE_MAJOR_VERSION 0 -#define SCM_OBJCODE_MINOR_VERSION D +#define SCM_OBJCODE_MINOR_VERSION E #define SCM_OBJCODE_MAJOR_VERSION_STRING \ SCM_CPP_STRINGIFY(SCM_OBJCODE_MAJOR_VERSION) #define SCM_OBJCODE_MINOR_VERSION_STRING \ diff --git a/libguile/vm-i-system.c b/libguile/vm-i-system.c index 0662f8188..ac237e5b5 100644 --- a/libguile/vm-i-system.c +++ b/libguile/vm-i-system.c @@ -411,61 +411,62 @@ VM_DEFINE_INSTRUCTION (30, long_toplevel_set, "long-toplevel-set", 2, 1, 0) * branch and jump */ -/* offset must be a signed 16 bit int!!! */ +/* offset must be at least 24 bits wide, and signed */ #define FETCH_OFFSET(offset) \ { \ - int h = FETCH (); \ - int l = FETCH (); \ - offset = (h << 8) + l; \ + offset = FETCH () << 16; \ + offset += FETCH () << 8; \ + offset += FETCH (); \ + offset -= (offset & (1<<23)) << 1; \ } #define BR(p) \ { \ - scm_t_int16 offset; \ + scm_t_int32 offset; \ FETCH_OFFSET (offset); \ if (p) \ - ip += ((scm_t_ptrdiff)offset) * 8 - (((unsigned long)ip) % 8); \ + ip += offset; \ NULLSTACK (1); \ DROP (); \ NEXT; \ } -VM_DEFINE_INSTRUCTION (31, br, "br", 2, 0, 0) +VM_DEFINE_INSTRUCTION (31, br, "br", 3, 0, 0) { - scm_t_int16 offset; + scm_t_int32 offset; FETCH_OFFSET (offset); - ip += ((scm_t_ptrdiff)offset) * 8 - (((unsigned long)ip) % 8); + ip += offset; NEXT; } -VM_DEFINE_INSTRUCTION (32, br_if, "br-if", 2, 0, 0) +VM_DEFINE_INSTRUCTION (32, br_if, "br-if", 3, 0, 0) { BR (!SCM_FALSEP (*sp)); } -VM_DEFINE_INSTRUCTION (33, br_if_not, "br-if-not", 2, 0, 0) +VM_DEFINE_INSTRUCTION (33, br_if_not, "br-if-not", 3, 0, 0) { BR (SCM_FALSEP (*sp)); } -VM_DEFINE_INSTRUCTION (34, br_if_eq, "br-if-eq", 2, 0, 0) +VM_DEFINE_INSTRUCTION (34, br_if_eq, "br-if-eq", 3, 0, 0) { sp--; /* underflow? */ BR (SCM_EQ_P (sp[0], sp[1])); } -VM_DEFINE_INSTRUCTION (35, br_if_not_eq, "br-if-not-eq", 2, 0, 0) +VM_DEFINE_INSTRUCTION (35, br_if_not_eq, "br-if-not-eq", 3, 0, 0) { sp--; /* underflow? */ BR (!SCM_EQ_P (sp[0], sp[1])); } -VM_DEFINE_INSTRUCTION (36, br_if_null, "br-if-null", 2, 0, 0) +VM_DEFINE_INSTRUCTION (36, br_if_null, "br-if-null", 3, 0, 0) { BR (SCM_NULLP (*sp)); } -VM_DEFINE_INSTRUCTION (37, br_if_not_null, "br-if-not-null", 2, 0, 0) +VM_DEFINE_INSTRUCTION (37, br_if_not_null, "br-if-not-null", 3, 0, 0) { BR (!SCM_NULLP (*sp)); } @@ -642,15 +643,15 @@ VM_DEFINE_INSTRUCTION (42, call_nargs, "call/nargs", 0, 0, 1) goto vm_call; } -VM_DEFINE_INSTRUCTION (43, mv_call, "mv-call", 3, -1, 1) +VM_DEFINE_INSTRUCTION (43, mv_call, "mv-call", 4, -1, 1) { SCM x; - scm_t_int16 offset; + scm_t_int32 offset; scm_t_uint8 *mvra; nargs = FETCH (); FETCH_OFFSET (offset); - mvra = ip + ((scm_t_ptrdiff)offset) * 8 - ((unsigned long)ip) % 8; + mvra = ip + offset; x = sp[-nargs]; diff --git a/libguile/vm.c b/libguile/vm.c index d41c8cd41..cd730511f 100644 --- a/libguile/vm.c +++ b/libguile/vm.c @@ -180,9 +180,8 @@ static SCM really_make_boot_program (long nargs) { SCM u8vec; - scm_t_uint8 text[] = { scm_op_mv_call, 0, 0, 1, - scm_op_make_int8_1, scm_op_nop, scm_op_nop, scm_op_nop, - scm_op_halt }; + scm_t_uint8 text[] = { scm_op_mv_call, 0, 0, 0, 1, + scm_op_make_int8_1, scm_op_halt }; struct scm_objcode *bp; SCM ret; diff --git a/module/language/assembly.scm b/module/language/assembly.scm index 683da6cc1..2b22fd834 100644 --- a/module/language/assembly.scm +++ b/module/language/assembly.scm @@ -72,7 +72,7 @@ '(nop))) (define (align-block addr) - (code-alignment addr *block-alignment* 0)) + '()) (define (align-code code addr alignment header-len) `(,@(code-alignment addr alignment header-len) diff --git a/module/language/assembly/compile-bytecode.scm b/module/language/assembly/compile-bytecode.scm index e8bba9e7e..5a8098112 100644 --- a/module/language/assembly/compile-bytecode.scm +++ b/module/language/assembly/compile-bytecode.scm @@ -55,6 +55,10 @@ (define (write-uint16-le x) (write-byte (logand x 255)) (write-byte (logand (ash x -8) 255))) + (define (write-uint24-be x) + (write-byte (logand (ash x -16) 255)) + (write-byte (logand (ash x -8) 255)) + (write-byte (logand x 255))) (define (write-uint32-be x) (write-byte (logand (ash x -24) 255)) (write-byte (logand (ash x -16) 255)) @@ -85,12 +89,10 @@ ;; Ew! (for-each write-byte (bytevector->u8-list bv))) (define (write-break label) - (let ((offset (- (assq-ref labels label) - (logand (+ (get-addr) 2) (lognot #x7))))) - (cond ((not (= 0 (modulo offset 8))) (error "unaligned jump" offset)) - ((>= offset (ash 1 18)) (error "jump too far forward" offset)) - ((< offset (- (ash 1 18))) (error "jump too far backwards" offset)) - (else (write-uint16-be (ash offset -3)))))) + (let ((offset (- (assq-ref labels label) (+ (get-addr) 3)))) + (cond ((>= offset (ash 1 23)) (error "jump too far forward" offset)) + ((< offset (- (ash 1 23))) (error "jump too far backwards" offset)) + (else (write-uint24-be offset))))) (let ((inst (car asm)) (args (cdr asm)) diff --git a/module/language/assembly/decompile-bytecode.scm b/module/language/assembly/decompile-bytecode.scm index 511c6ccc6..915e101b8 100644 --- a/module/language/assembly/decompile-bytecode.scm +++ b/module/language/assembly/decompile-bytecode.scm @@ -43,11 +43,11 @@ (define (br-instruction? x) (memq x '(br br-if br-if-not br-if-eq br-if-not-eq br-if-null br-if-not-null))) -(define (bytes->s16 a b) - (let ((x (+ (ash a 8) b))) - (if (zero? (logand (ash 1 15) x)) +(define (bytes->s24 a b c) + (let ((x (+ (ash a 16) (ash b 8) c))) + (if (zero? (logand (ash 1 23) x)) x - (- x (ash 1 16))))) + (- x (ash 1 24))))) ;; FIXME: this is a little-endian disassembly!!! (define (decode-load-program pop) @@ -60,9 +60,8 @@ (%unused-pad (begin (pop) (pop) (pop) (pop))) (labels '()) (i 0)) - (define (ensure-label rel1 rel2) - (let ((where (+ (logand i (lognot #x7)) - (* (bytes->s16 rel1 rel2) 8)))) + (define (ensure-label rel1 rel2 rel3) + (let ((where (+ i (bytes->s24 rel1 rel2 rel3)))) (or (assv-ref labels where) (begin (let ((l (gensym ":L"))) @@ -87,9 +86,9 @@ (else (let ((exp (decode-bytecode sub-pop))) (pmatch exp - ((,br ,rel1 ,rel2) (guard (br-instruction? br)) - (lp (cons `(,br ,(ensure-label rel1 rel2)) out))) - ((mv-call ,n ,rel1 ,rel2) + ((,br ,rel1 ,rel2 ,rel3) (guard (br-instruction? br)) + (lp (cons `(,br ,(ensure-label rel1 rel2 rel3)) out))) + ((mv-call ,n ,rel1 ,rel2 ,rel3) (lp (cons `(mv-call ,n ,(ensure-label rel1 rel2)) out))) (else (lp (cons exp out)))))))))) |