Cranelift: Remove resumable traps

cranelift/codegen/meta/src/shared/instructions.rs

@@ -144,20 +144,6 @@ fn define_control_flow(
         .can_trap(),
     );
 
-    ig.push(
-        Inst::new(
-            "resumable_trap",
-            r#"
-        A resumable trap.
-
-        This instruction allows non-conditional traps to be used as non-terminal instructions.
-        "#,
-            &formats.trap,
-        )
-        .operands_in(vec![Operand::new("code", &imm.trapcode)])
-        .can_trap(),
-    );
-
     ig.push(
         Inst::new(
             "trapnz",
@@ -175,23 +161,6 @@ fn define_control_flow(
         .can_trap(),
     );
 
-    ig.push(
-        Inst::new(
-            "resumable_trapnz",
-            r#"
-        A resumable trap to be called when the passed condition is non-zero.
-
-        If ``c`` is zero, execution continues at the following instruction.
-        "#,
-            &formats.cond_trap,
-        )
-        .operands_in(vec![
-            Operand::new("c", ScalarTruthy).with_doc("Controlling value to test"),
-            Operand::new("code", &imm.trapcode),
-        ])
-        .can_trap(),
-    );
-
     ig.push(
         Inst::new(
             "return",

cranelift/codegen/src/ir/instructions.rs

@@ -193,14 +193,6 @@ impl Opcode {
     pub fn constraints(self) -> OpcodeConstraints {
         OPCODE_CONSTRAINTS[self as usize - 1]
     }
-
-    /// Returns true if the instruction is a resumable trap.
-    pub fn is_resumable_trap(&self) -> bool {
-        match self {
-            Opcode::ResumableTrap | Opcode::ResumableTrapnz => true,
-            _ => false,
-        }
-    }
 }
 
 // This trait really belongs in cranelift-reader where it is used by the `.clif` file parser, but since

cranelift/codegen/src/ir/trapcode.rs

@@ -46,7 +46,6 @@ pub enum TrapCode {
     UnreachableCodeReached,
 
     /// Execution has potentially run too long and may be interrupted.
-    /// This trap is resumable.
     Interrupt,
 
     /// A user-defined trap code.

cranelift/codegen/src/isa/aarch64/lower.isle

@@ -1936,11 +1936,6 @@
 (rule (lower (trap trap_code))
       (side_effect (udf trap_code)))
 
-;;;; Rules for `resumable_trap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(rule (lower (resumable_trap trap_code))
-      (side_effect (udf trap_code)))
-
 ;;;; Rules for `select` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 (rule (lower (has_type ty

cranelift/codegen/src/isa/riscv64/lower.isle

@@ -2027,11 +2027,6 @@
   (lower (trap code))
   (udf code))
 
-;;;;;  Rules for `resumable_trap`;;;;;;;;;
-(rule
-  (lower (resumable_trap code))
-  (udf code))
-
 ;;;;;  Rules for `uload8`;;;;;;;;;
 (rule (lower (uload8 flags addr offset))
   (gen_load (amode addr offset) (LoadOP.Lbu) flags))

cranelift/codegen/src/isa/s390x/lower.isle

@@ -3800,12 +3800,6 @@
       (side_effect (trap_impl trap_code)))
 
 
-;;;; Rules for `resumable_trap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(rule (lower (resumable_trap trap_code))
-      (side_effect (trap_impl trap_code)))
-
-
 ;;;; Rules for `trapz` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 (rule (lower (trapz val trap_code))
@@ -3818,12 +3812,6 @@
       (side_effect (trap_if_bool (value_nonzero val) trap_code)))
 
 
-;;;; Rules for `resumable_trapnz` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(rule (lower (resumable_trapnz val trap_code))
-      (side_effect (trap_if_bool (value_nonzero val) trap_code)))
-
-
 ;;;; Rules for `debugtrap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 (rule (lower (debugtrap))

cranelift/codegen/src/isa/x64/lower.isle

@@ -1821,11 +1821,6 @@
         (x64_add_with_flags_paired ty b a)
         (trap_if (CC.B) tc)))
 
-;;;; Rules for `resumable_trap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(rule (lower (resumable_trap code))
-      (side_effect (x64_ud2 code)))
-
 ;;;; Rules for `return` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 ;; N.B.: the Ret itself is generated by the ABI.

cranelift/codegen/src/legalizer/mod.rs

@@ -64,8 +64,7 @@ pub fn simple_legalize(func: &mut ir::Function, cfg: &mut ControlFlowGraph, isa:
             match pos.func.dfg.insts[inst] {
                 // control flow
                 InstructionData::CondTrap {
-                    opcode:
-                        opcode @ (ir::Opcode::Trapnz | ir::Opcode::Trapz | ir::Opcode::ResumableTrapnz),
+                    opcode: opcode @ (ir::Opcode::Trapnz | ir::Opcode::Trapz),
                     arg,
                     code,
                 } => {
@@ -283,7 +282,7 @@ fn expand_cond_trap(
     // Parse the instruction.
     let trapz = match opcode {
         ir::Opcode::Trapz => true,
-        ir::Opcode::Trapnz | ir::Opcode::ResumableTrapnz => false,
+        ir::Opcode::Trapnz => false,
         _ => panic!("Expected cond trap: {}", func.dfg.display_inst(inst)),
     };
 
@@ -331,10 +330,6 @@ fn expand_cond_trap(
         ir::Opcode::Trapz | ir::Opcode::Trapnz => {
             pos.ins().trap(code);
         }
-        ir::Opcode::ResumableTrapnz => {
-            pos.ins().resumable_trap(code);
-            pos.ins().jump(new_block_resume, &[]);
-        }
         _ => unreachable!(),
     }
 

cranelift/filetests/filetests/isa/s390x/traps.clif

@@ -2,7 +2,7 @@ test compile precise-output
 target s390x
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;; TRAP/RESUMABLE_TRAP
+;; TRAP
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 function %trap() {
@@ -18,19 +18,6 @@ block0:
 ; block0: ; offset 0x0
 ;   .byte 0x00, 0x00 ; trap: user0
 
-function %resumable_trap() {
-block0:
-  trap user0
-}
-
-; VCode:
-; block0:
-;   .word 0x0000 # trap=user0
-;
-; Disassembled:
-; block0: ; offset 0x0
-;   .byte 0x00, 0x00 ; trap: user0
-
 function %trapz(i64) {
 block0(v0: i64):
   v1 = iconst.i64 42
@@ -83,32 +70,6 @@ block0(v0: i64):
 ; block2: ; offset 0xe
 ;   .byte 0x00, 0x00 ; trap: user0
 
-function %resumable_trapnz(i64) {
-block0(v0: i64):
-  v1 = iconst.i64 42
-  v2 = icmp eq v0, v1
-  trapnz v2, user0
-  return
-}
-
-; VCode:
-; block0:
-;   clgfi %r2, 42
-;   jge label2 ; jg label1
-; block1:
-;   br %r14
-; block2:
-;   .word 0x0000 # trap=user0
-;
-; Disassembled:
-; block0: ; offset 0x0
-;   clgfi %r2, 0x2a
-;   jge 0xe
-; block1: ; offset 0xc
-;   br %r14
-; block2: ; offset 0xe
-;   .byte 0x00, 0x00 ; trap: user0
-
 function %h() {
 block0:
   debugtrap
@@ -124,4 +85,3 @@ block0:
 ; block0: ; offset 0x0
 ;   .byte 0x00, 0x01
 ;   br %r14
-

cranelift/fuzzgen/src/function_generator.rs

@@ -888,9 +888,7 @@ static OPCODE_SIGNATURES: Lazy<Vec<OpcodeSignature>> = Lazy::new(|| {
                 (Opcode::Debugtrap),
                 (Opcode::Trap),
                 (Opcode::Trapz),
-                (Opcode::ResumableTrap),
                 (Opcode::Trapnz),
-                (Opcode::ResumableTrapnz),
                 (Opcode::CallIndirect, &[I32]),
                 (Opcode::FuncAddr),
                 (Opcode::X86Pshufb),

cranelift/interpreter/src/step.rs

@@ -353,10 +353,8 @@ where
         }
         Opcode::Trap => ControlFlow::Trap(CraneliftTrap::User(trap_code())),
         Opcode::Debugtrap => ControlFlow::Trap(CraneliftTrap::Debug),
-        Opcode::ResumableTrap => ControlFlow::Trap(CraneliftTrap::Resumable),
         Opcode::Trapz => trap_when(!arg(0).into_bool()?, CraneliftTrap::User(trap_code())),
         Opcode::Trapnz => trap_when(arg(0).into_bool()?, CraneliftTrap::User(trap_code())),
-        Opcode::ResumableTrapnz => trap_when(arg(0).into_bool()?, CraneliftTrap::Resumable),
         Opcode::Return => ControlFlow::Return(args()),
         Opcode::Call | Opcode::ReturnCall => {
             let func_ref = if let InstructionData::Call { func_ref, .. } = inst {
@@ -1330,8 +1328,6 @@ pub enum CraneliftTrap {
     User(TrapCode),
     #[error("user debug")]
     Debug,
-    #[error("resumable")]
-    Resumable,
 }
 
 /// Compare two values using the given integer condition `code`.

fuzz/fuzz_targets/cranelift-fuzzgen.rs

@@ -107,7 +107,6 @@ impl Default for Statistics {
         // Pre-Register all trap codes since we can't modify this hashmap atomically.
         let mut run_result_trap = HashMap::new();
         run_result_trap.insert(CraneliftTrap::Debug, AtomicU64::new(0));
-        run_result_trap.insert(CraneliftTrap::Resumable, AtomicU64::new(0));
         for trapcode in TrapCode::non_user_traps() {
             run_result_trap.insert(CraneliftTrap::User(*trapcode), AtomicU64::new(0));
         }