From ab7e9ab016e5c28f1647bd399277fc85b3b24dc8 Mon Sep 17 00:00:00 2001
From: Nick Fitzgerald <fitzgen@gmail.com>
Date: Fri, 14 Jun 2024 12:34:48 -0700
Subject: [PATCH] Cranelift: Traps need not be considered GC safepoints anymore

After https://github.com/bytecodealliance/wasmtime/pull/8809, the mutator cannot
resume from a trap so we don't need to consider them safepoints, as no
GC-managed references are live after the trap. The one exception being the
`debugtrap` CLIF instruction, which is technically still a resumable trap, but
which exists only for emitting the equivalent of an `int3` breakpoint
instruction for pausing in a debugger to inspect state, and should never be used
for mutator-collector interactions.
---
 cranelift/codegen/src/isa/aarch64/inst/mod.rs | 5 +----
 cranelift/codegen/src/isa/riscv64/inst/mod.rs | 5 +----
 cranelift/codegen/src/isa/s390x/inst/mod.rs   | 8 +-------
 cranelift/codegen/src/isa/x64/inst/mod.rs     | 5 +----
 4 files changed, 4 insertions(+), 19 deletions(-)

diff --git a/cranelift/codegen/src/isa/aarch64/inst/mod.rs b/cranelift/codegen/src/isa/aarch64/inst/mod.rs
index 6fc2a9598373..54e2a4f77d69 100644
--- a/cranelift/codegen/src/isa/aarch64/inst/mod.rs
+++ b/cranelift/codegen/src/isa/aarch64/inst/mod.rs
@@ -1114,10 +1114,7 @@ impl MachInst for Inst {
 
     fn is_safepoint(&self) -> bool {
         match self {
-            &Inst::Call { .. }
-            | &Inst::CallInd { .. }
-            | &Inst::TrapIf { .. }
-            | &Inst::Udf { .. } => true,
+            Inst::Call { .. } | Inst::CallInd { .. } => true,
             _ => false,
         }
     }
diff --git a/cranelift/codegen/src/isa/riscv64/inst/mod.rs b/cranelift/codegen/src/isa/riscv64/inst/mod.rs
index eee4af1cc9d7..a846c6024974 100644
--- a/cranelift/codegen/src/isa/riscv64/inst/mod.rs
+++ b/cranelift/codegen/src/isa/riscv64/inst/mod.rs
@@ -731,10 +731,7 @@ impl MachInst for Inst {
 
     fn is_safepoint(&self) -> bool {
         match self {
-            &Inst::Call { .. }
-            | &Inst::CallInd { .. }
-            | &Inst::TrapIf { .. }
-            | &Inst::Udf { .. } => true,
+            Inst::Call { .. } | Inst::CallInd { .. } => true,
             _ => false,
         }
     }
diff --git a/cranelift/codegen/src/isa/s390x/inst/mod.rs b/cranelift/codegen/src/isa/s390x/inst/mod.rs
index b9550a9839e0..6b1d9f531a4b 100644
--- a/cranelift/codegen/src/isa/s390x/inst/mod.rs
+++ b/cranelift/codegen/src/isa/s390x/inst/mod.rs
@@ -1073,13 +1073,7 @@ impl MachInst for Inst {
 
     fn is_safepoint(&self) -> bool {
         match self {
-            &Inst::Call { .. }
-            | &Inst::CallInd { .. }
-            | &Inst::Trap { .. }
-            | Inst::TrapIf { .. }
-            | &Inst::CmpTrapRR { .. }
-            | &Inst::CmpTrapRSImm16 { .. }
-            | &Inst::CmpTrapRUImm16 { .. } => true,
+            Inst::Call { .. } | Inst::CallInd { .. } => true,
             _ => false,
         }
     }
diff --git a/cranelift/codegen/src/isa/x64/inst/mod.rs b/cranelift/codegen/src/isa/x64/inst/mod.rs
index 34e6647f6213..fd8c375e6ea1 100644
--- a/cranelift/codegen/src/isa/x64/inst/mod.rs
+++ b/cranelift/codegen/src/isa/x64/inst/mod.rs
@@ -2687,10 +2687,7 @@ impl MachInst for Inst {
 
     fn is_safepoint(&self) -> bool {
         match self {
-            Inst::CallKnown { .. }
-            | Inst::CallUnknown { .. }
-            | Inst::TrapIf { .. }
-            | Inst::Ud2 { .. } => true,
+            Inst::CallKnown { .. } | Inst::CallUnknown { .. } => true,
             _ => false,
         }
     }