diff options
author | Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com> | 2021-01-12 17:03:54 -0500 |
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committer | Alan Wu <XrXr@users.noreply.github.com> | 2021-10-20 18:19:27 -0400 |
commit | ef08af93769982047e59356d76c7e72a67970335 (patch) | |
tree | 4835b538e2012d6ad28dba2c1f65afc95159f89c | |
parent | 3a74011ff8e5b9b4bf07ef72d249d08b8c13c57e (diff) |
Progress on code invalidation
-rw-r--r-- | ujit_codegen.c | 14 | ||||
-rw-r--r-- | ujit_codegen.h | 5 | ||||
-rw-r--r-- | ujit_core.c | 29 | ||||
-rw-r--r-- | ujit_core.h | 2 |
4 files changed, 41 insertions, 9 deletions
diff --git a/ujit_codegen.c b/ujit_codegen.c index 8ba71bf37f..4833e4ab1f 100644 --- a/ujit_codegen.c +++ b/ujit_codegen.c @@ -133,8 +133,7 @@ uint8_t* ujit_compile_entry(const rb_iseq_t *iseq, uint32_t insn_idx) ctx_t ctx = { 0 }; // Compile the block starting at this instruction - uint32_t num_instrs = 0; - ujit_compile_block(iseq, insn_idx, &ctx, &num_instrs); + uint32_t num_instrs = ujit_compile_block(iseq, insn_idx, &ctx); // If no instructions were compiled if (num_instrs == 0) { @@ -154,8 +153,8 @@ uint8_t* ujit_compile_entry(const rb_iseq_t *iseq, uint32_t insn_idx) /* Compile a sequence of bytecode instructions starting at `insn_idx`. */ -void -ujit_compile_block(const rb_iseq_t *iseq, uint32_t insn_idx, ctx_t* ctx, uint32_t* num_instrs) +uint32_t +ujit_compile_block(/*version_t* version,*/ const rb_iseq_t *iseq, uint32_t insn_idx, ctx_t* ctx) { assert (cb != NULL); VALUE *encoded = iseq->body->iseq_encoded; @@ -175,10 +174,13 @@ ujit_compile_block(const rb_iseq_t *iseq, uint32_t insn_idx, ctx_t* ctx, uint32_ // Initialize JIT state object jitstate_t jit = { + NULL, iseq, insn_idx }; + uint32_t num_instrs = 0; + // For each instruction to compile for (;;) { // Set the current instruction @@ -209,7 +211,7 @@ ujit_compile_block(const rb_iseq_t *iseq, uint32_t insn_idx, ctx_t* ctx, uint32_ // Move to the next instruction p_last_op = p_desc; insn_idx += insn_len(opcode); - (*num_instrs)++; + num_instrs++; // If this instruction terminates this block if (p_desc->is_branch) { @@ -234,6 +236,8 @@ ujit_compile_block(const rb_iseq_t *iseq, uint32_t insn_idx, ctx_t* ctx, uint32_ pc += insn_len(opcode); } } + + return num_instrs; } static bool diff --git a/ujit_codegen.h b/ujit_codegen.h index 413ecb35ac..d01a73bde0 100644 --- a/ujit_codegen.h +++ b/ujit_codegen.h @@ -11,6 +11,9 @@ codeblock_t* ocb; // Code generation state typedef struct JITState { + // Block version being compiled + version_t* version; + // Instruction sequence this is associated with const rb_iseq_t *iseq; @@ -42,7 +45,7 @@ typedef struct OpDesc uint8_t* ujit_compile_entry(const rb_iseq_t *iseq, uint32_t insn_idx); -void ujit_compile_block(const rb_iseq_t *iseq, uint32_t insn_idx, ctx_t* ctx, uint32_t* num_instrs); +uint32_t ujit_compile_block(const rb_iseq_t *iseq, uint32_t insn_idx, ctx_t* ctx); void ujit_init_codegen(void); diff --git a/ujit_core.c b/ujit_core.c index c3166d0f09..c316675185 100644 --- a/ujit_core.c +++ b/ujit_core.c @@ -95,9 +95,8 @@ version_t* gen_block_version(blockid_t blockid, const ctx_t* ctx) // Compile the block version ctx_t ctx_copy = *ctx; - uint32_t num_instrs = 0; p_version->start_pos = cb->write_pos; - ujit_compile_block(blockid.iseq, blockid.idx, &ctx_copy, &num_instrs); + ujit_compile_block(blockid.iseq, blockid.idx, &ctx_copy); p_version->end_pos = cb->write_pos; // Keep track of the new block version @@ -159,7 +158,7 @@ uint8_t* branch_stub_hit(uint32_t branch_idx, uint32_t target_idx) } // Get a version or stub corresponding to a branch target -// TODO: need incoming and target versioning contexts +// TODO: need incoming and target contexts uint8_t* get_branch_target( blockid_t target, const ctx_t* ctx, @@ -239,6 +238,30 @@ void gen_branch( num_branches++; } +// Invalidate one specific block version +void invalidate(version_t* version) +{ + // All branches jumping to the block should be atomically patched with jumps going to a stub instead. + + // There can also be other blocks falling through to the invalidated block because they immediately precede it. + // - If an incoming fall-through branch is too short to be patched, we may need to invalidate its block + // - This may not be an issue in practice, because the block we go to could have space + // - We can force any block that may need to be invalidated to have sufficient space to contain a jump to a stub + + // If the block is an entry point, it needs to be unmapped from its iseq + // Unmap/remap anything at this iseq/idx + + // Optional: may want to recompile a new deoptimized entry point + // Call continuation addresses on the stack can also be atomically replaced by jumps going to the stub. + + + + + + + +} + int blockid_cmp(st_data_t arg0, st_data_t arg1) { const blockid_t *block0 = (const blockid_t*)arg0; diff --git a/ujit_core.h b/ujit_core.h index 4c80bbc5d4..07a18ed727 100644 --- a/ujit_core.h +++ b/ujit_core.h @@ -122,6 +122,8 @@ void gen_branch( branchgen_fn gen_fn ); +void invalidate(version_t* version); + void ujit_init_core(void); #endif // #ifndef UJIT_CORE_H |