Reland "[riscv] Fix Check failed in bind_to"

This is a reland of commit fdb5de2

Original change's description:
> [riscv] Fix Check failed in bind_to
>
> The trampoline should be emitted before the constant pool.
>
> Bug: 420232092
>
> Change-Id: I3a909b122607e37aca9d8765f28810ec74d5dc0b
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6578135
> Auto-Submit: Yahan Lu (LuYahan) <yahan@iscas.ac.cn>
> Reviewed-by: Ji Qiu <qiuji@iscas.ac.cn>
> Commit-Queue: Ji Qiu <qiuji@iscas.ac.cn>
> Cr-Commit-Position: refs/heads/main@{#100480}

Bug: 420232092
Change-Id: I1fac1ed8c349383ef4510abea338b3d695ed57ab
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6595668
Commit-Queue: Ji Qiu <qiuji@iscas.ac.cn>
Reviewed-by: Ji Qiu <qiuji@iscas.ac.cn>
Cr-Commit-Position: refs/heads/main@{#100745}

Author: luyahan

src/codegen/riscv/assembler-riscv.cc

@@ -720,8 +720,8 @@ void Assembler::bind_to(Label* L, int pos) {
             trampoline_pos = get_trampoline_entry(fixup_pos);
             CHECK_NE(trampoline_pos, kInvalidSlotPos);
           }
-          CHECK((trampoline_pos - fixup_pos) <= kMaxBranchOffset);
           DEBUG_PRINTF("\t\ttrampolining: %d\n", trampoline_pos);
+          CHECK((trampoline_pos - fixup_pos) <= kMaxBranchOffset);
           target_at_put(fixup_pos, trampoline_pos, false);
           fixup_pos = trampoline_pos;
         }
@@ -1498,6 +1498,7 @@ void Assembler::BlockTrampolinePoolFor(int instructions) {
 }
 
 void Assembler::CheckTrampolinePool() {
+  if (trampoline_emitted_) return;
   // Some small sequences of instructions must not be broken up by the
   // insertion of a trampoline pool; such sequences are protected by setting
   // either trampoline_pool_blocked_nesting_ or no_trampoline_pool_before_,
@@ -1519,7 +1520,6 @@ void Assembler::CheckTrampolinePool() {
     return;
   }
 
-  DCHECK(!trampoline_emitted_);
   DCHECK_GE(unbound_labels_count_, 0);
   if (unbound_labels_count_ > 0) {
     // First we emit jump, then we emit trampoline pool.

src/codegen/riscv/assembler-riscv.h

@@ -305,6 +305,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase,
   // See Assembler::CheckConstPool for more info.
   void EmitPoolGuard();
 
+  void FinishCode() { ForceConstantPoolEmissionWithoutJump(); }
+
 #if defined(V8_TARGET_ARCH_RISCV64)
   static void set_target_value_at(
       Address pc, uint64_t target,
@@ -620,6 +622,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase,
     }
   }
 
+  inline int next_buffer_check() { return next_buffer_check_; }
+
   friend class VectorUnit;
   class VectorUnit {
    public:
@@ -731,16 +735,19 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase,
 
   // Block the emission of the trampoline pool before pc_offset.
   void BlockTrampolinePoolBefore(int pc_offset) {
-    if (no_trampoline_pool_before_ < pc_offset)
+    if (no_trampoline_pool_before_ < pc_offset) {
+      DEBUG_PRINTF("\tBlockTrampolinePoolBefore %d\n", pc_offset);
       no_trampoline_pool_before_ = pc_offset;
+    }
   }
 
   void StartBlockTrampolinePool() {
-    DEBUG_PRINTF("\tStartBlockTrampolinePool\n");
+    DEBUG_PRINTF("\tStartBlockTrampolinePool %d\n", pc_offset());
     trampoline_pool_blocked_nesting_++;
   }
 
   void EndBlockTrampolinePool() {
+    DEBUG_PRINTF("\tEndBlockTrampolinePool\n");
     trampoline_pool_blocked_nesting_--;
     DEBUG_PRINTF("\ttrampoline_pool_blocked_nesting:%d\n",
                  trampoline_pool_blocked_nesting_);
@@ -770,6 +777,10 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase,
 
   bool is_buffer_growth_blocked() const { return block_buffer_growth_; }
 
+  inline int ConstpoolComputesize() {
+    return constpool_.ComputeSize(Jump::kOmitted, Alignment::kOmitted);
+  }
+
  private:
   // Avoid overflows for displacements etc.
   static const int kMaximalBufferSize = 512 * MB;

src/codegen/riscv/macro-assembler-riscv.cc

@@ -4974,12 +4974,22 @@ void MacroAssembler::Jump(Register target, Condition cond, Register rs,
                           const Operand& rt) {
   DCHECK_WITH_MSG(t0 != target,
                   "don't use x5 as target for jumps to avoid RAS pollution");
-
-  BlockTrampolinePoolScope block_trampoline_pool(this);
   if (cond == cc_always) {
     jr(target);
+    DEBUG_PRINTF("\tCheckTrampolinePool pc_offset:%d %d\n", pc_offset(),
+                 next_buffer_check() - ConstpoolComputesize());
+    if (!is_trampoline_emitted() && v8_flags.debug_code &&
+        pc_offset() >= (next_buffer_check() - ConstpoolComputesize())) {
+      // Debug mode will emit more instrs than Release mode.
+      // so we need to check trampoline pool before Constant pool.
+      // Here need to emit trampoline first.
+      // Jump(ra, al) will block trampoline pool for 1 instr.
+      nop();
+      CheckTrampolinePool();
+    }
     ForceConstantPoolEmissionWithoutJump();
   } else {
+    BlockTrampolinePoolScope block_trampoline_pool(this);
     BRANCH_ARGS_CHECK(cond, rs, rt);
     Branch(kInstrSize * 2, NegateCondition(cond), rs, rt);
     jr(target);
@@ -5393,9 +5403,6 @@ void MacroAssembler::StoreReturnAddressAndCall(Register target) {
 
 void MacroAssembler::Ret(Condition cond, Register rs, const Operand& rt) {
   Jump(ra, cond, rs, rt);
-  if (cond == al) {
-    ForceConstantPoolEmissionWithoutJump();
-  }
 }
 
 void MacroAssembler::BranchLong(Label* L) {