[wasm] Avoid spilling refs to the stack in gsharedvt wrappers, those functions don...

Co-authored-by: Zoltan Varga <vargaz@gmail.com>

diff --git a/src/mono/mono/mini/mini-llvm.c b/src/mono/mono/mini/mini-llvm.c
index 0915473..c06200e 100644 (file)
--- a/src/mono/mono/mini/mini-llvm.c
+++ b/src/mono/mono/mini/mini-llvm.c
@@ -173,6 +173,7 @@ typedef struct {
        gboolean llvm_only;
        gboolean has_got_access;
        gboolean emit_dummy_arg;
+       gboolean has_safepoints;
        int this_arg_pindex, rgctx_arg_pindex;
        LLVMValueRef imt_rgctx_loc;
        GHashTable *llvm_types;
@@ -3559,7 +3560,7 @@ emit_entry_bb (EmitContext *ctx, LLVMBuilderRef builder)
 #ifdef TARGET_WASM
                // For GC stack scanning to work, have to spill all reference variables to the stack
                // Some ref variables have type intptr
-               if (MONO_TYPE_IS_REFERENCE (var->inst_vtype) || var->inst_vtype->type == MONO_TYPE_I)
+               if (ctx->has_safepoints && (MONO_TYPE_IS_REFERENCE (var->inst_vtype) || var->inst_vtype->type == MONO_TYPE_I))
                        var->flags |= MONO_INST_INDIRECT;
 #endif
 
@@ -8624,6 +8625,20 @@ emit_method_inner (EmitContext *ctx)
                        }
                }
        }
+       if (cfg->method->wrapper_type) {
+               WrapperInfo *info = mono_marshal_get_wrapper_info (cfg->method);
+
+               switch (info->subtype) {
+               case WRAPPER_SUBTYPE_GSHAREDVT_IN:
+               case WRAPPER_SUBTYPE_GSHAREDVT_OUT:
+               case WRAPPER_SUBTYPE_GSHAREDVT_IN_SIG:
+               case WRAPPER_SUBTYPE_GSHAREDVT_OUT_SIG:
+                       /* Arguments are not used after the call */
+                       requires_safepoint = FALSE;
+                       break;
+               }
+       }
+       ctx->has_safepoints = requires_safepoint;
 
 #ifndef MONO_LLVM_LOADED
        if (!cfg->llvm_only && mono_threads_are_safepoints_enabled () && requires_safepoint) {