diff options
Diffstat (limited to 'upb/pb/compile_decoder_x64.dasc')
| -rw-r--r-- | upb/pb/compile_decoder_x64.dasc | 82 |
1 files changed, 51 insertions, 31 deletions
diff --git a/upb/pb/compile_decoder_x64.dasc b/upb/pb/compile_decoder_x64.dasc index 9eec6a5..180017f 100644 --- a/upb/pb/compile_decoder_x64.dasc +++ b/upb/pb/compile_decoder_x64.dasc @@ -133,33 +133,44 @@ | add PTR, 1 |.endmacro +#define DECODE_EOF -3 + +static upb_func *gethandler(const upb_handlers *h, upb_selector_t sel) { + return h ? upb_handlers_gethandler(h, sel) : NULL; +} + +// Defines an "assembly label" for the current code generation offset. +// This label exists *purely* for debugging purposes: it is emitted into +// the .so, and printed as part of JIT debugging output when UPB_JIT_LOAD_SO is +// defined. +// +// We would define this in the .c file except that it conditionally defines a +// pclabel. static void asmlabel(jitcompiler *jc, const char *fmt, ...) { +#ifndef NDEBUG int ofs = jc->dynasm->section->ofs; assert(ofs != jc->lastlabelofs); jc->lastlabelofs = ofs; +#endif + +#ifndef UPB_JIT_LOAD_SO + UPB_UNUSED(jc); + UPB_UNUSED(fmt); +#else va_list args; va_start(args, fmt); - - // Run once to get the length of the string. - va_list args_copy; - va_copy(args_copy, args); - int len = vsnprintf(NULL, 0, fmt, args_copy); - va_end(args_copy); - - char *str = malloc(len + 1); // + 1 for NULL terminator. - if (!str) exit(1); - int written = vsnprintf(str, len + 1, fmt, args); + char *str = upb_vasprintf(fmt, args); va_end(args); - UPB_ASSERT_VAR(written, written == len); - uint32_t label = jc->pclabel_count++; - dasm_growpc(jc, jc->pclabel_count); - |=>label: - upb_inttable_insert(&jc->asmlabels, label, upb_value_ptr(str)); -} - -static upb_func *gethandler(const upb_handlers *h, upb_selector_t sel) { - return h ? upb_handlers_gethandler(h, sel) : NULL; + int pclabel = alloc_pclabel(jc); + // Normally we would prefer to allocate this inline with the codegen, + // ie. + // |=>asmlabel(...) + // But since we do this conditionally, only when UPB_JIT_LOAD_SO is defined, + // we do it here instead. + |=>pclabel: + upb_inttable_insert(&jc->asmlabels, pclabel, upb_value_ptr(str)); +#endif } // Should only be called when the associated handler is known to exist. @@ -696,7 +707,7 @@ static void jitdispatch(jitcompiler *jc, // this characteristic. bool has_multi_wiretype = has_hash_entries; - |=>define_pclabel(jc, &method->dispatch): + |=>define_jmptarget(jc, &method->dispatch): |1: // Decode the field tag. | mov aword DECODER->checkpoint, PTR @@ -751,8 +762,17 @@ static void jitdispatch(jitcompiler *jc, | jne >5 } | shr rax, 16 + | + | // Load the machine code address from the table entry. + | // The table entry is relative to the dispatch->array jmptarget + | // (patchdispatch() took care of this) which is the same as + | // local label "4". The "lea" is really just trying to do + | // lea rax, [>4 + rax] + | // + | // But we can't write that directly for some reason, so we use + | // rdx as a temporary. | lea rdx, [>4] - |=>define_pclabel(jc, dispatch->array): + |=>define_jmptarget(jc, dispatch->array): |4: | add rax, rdx | ret @@ -812,7 +832,7 @@ static void jittag(jitcompiler *jc, uint64_t tag, int n, int ofs, | cmp eax, DECODE_MISMATCH | je >3 | cmp eax, DECODE_EOF - | je =>pclabel(jc, delimend) + | je =>jmptarget(jc, delimend) | jmp >5 |1: @@ -844,12 +864,12 @@ static void jittag(jitcompiler *jc, uint64_t tag, int n, int ofs, | je >4 |3: if (ofs == 0) { - | call =>pclabel(jc, &method->dispatch) + | call =>jmptarget(jc, &method->dispatch) | test rax, rax - | jz =>pclabel(jc, delimend) + | jz =>jmptarget(jc, delimend) | jmp rax } else { - | jmp =>pclabel(jc, jc->pc + ofs) + | jmp =>jmptarget(jc, jc->pc + ofs) } |4: | add PTR, n @@ -874,7 +894,7 @@ static void jitbytecode(jitcompiler *jc) { // Skipped for SETDISPATCH because it should point at the function // prologue, not the dispatch function that is emitted first. // TODO: optimize this to only define pclabels that are actually used. - |=>define_pclabel(jc, jc->pc): + |=>define_jmptarget(jc, jc->pc): } jc->pc++; @@ -936,8 +956,8 @@ static void jitbytecode(jitcompiler *jc) { // Emit function prologue for new method. asmlabel(jc, "0x%lx.parse.%s", pcofs(jc), msgname); - |=>define_pclabel(jc, op_pc): - |=>define_pclabel(jc, method): + |=>define_jmptarget(jc, op_pc): + |=>define_jmptarget(jc, method): | sub rsp, 8 break; @@ -1082,13 +1102,13 @@ static void jitbytecode(jitcompiler *jc) { break; case OP_CHECKDELIM: | cmp DELIMEND, PTR - | je =>pclabel(jc, jc->pc + longofs) + | je =>jmptarget(jc, jc->pc + longofs) break; case OP_CALL: - | call =>pclabel(jc, jc->pc + longofs) + | call =>jmptarget(jc, jc->pc + longofs) break; case OP_BRANCH: - | jmp =>pclabel(jc, jc->pc + longofs); + | jmp =>jmptarget(jc, jc->pc + longofs); break; case OP_RET: |9: |