From 97fcf583b7239ea17dbb73eae9438d21136eb2db Mon Sep 17 00:00:00 2001 From: Andy Wingo Date: Thu, 17 Sep 2009 14:58:31 +0200 Subject: 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. --- libguile/vm-i-system.c | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) (limited to 'libguile/vm-i-system.c') 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]; -- cgit v1.2.3