Uh oh!
There was an error while loading. Please reload this page.
[mono] Extend mono_gsharedvt_constrained_call for static calls and handle nullable value types - #94787
Conversation
…haredvt ref arguments if it is a nullable vtype.
ghost
commented
Nov 15, 2023
Tagging subscribers to 'os-ios': @steveisok, @akoeplinger, @kotlarmilos Issue DetailsDescriptionThis PR extends Fixes #94467
|
| memcpy (new_args, args, fsig->param_count * sizeof (gpointer)); | ||
| for (int i = 0; i < fsig->param_count; ++i) { | ||
| if (deref_args [i]) | ||
| // If the argument is a ref or nullable non-vtype, deref it |
There was a problem hiding this comment.
Isn't this information already known at the callsite in handle_constrained_gsharedvt_call and can be passed through deref_args? Also isn't deref_args supposed to be set only for valuetype args, why the check below?
There was a problem hiding this comment.
Is there a testcase which fails for this case ?
There was a problem hiding this comment.
The case we want handle here is handler.Test<bool?>(true);.
Isn't this information already known at the callsite in
handle_constrained_gsharedvt_calland can be passed throughderef_args?
Yes, this information already known at the callsite:
if(mini_is_gsharedvt_type(fsig->params[i])){MonoInst*is_deref;intderef_arg_reg;ins=mini_emit_get_gsharedvt_info_klass(cfg,mono_class_from_mono_type_internal(fsig->params[i]),MONO_RGCTX_INFO_CLASS_BOX_TYPE);deref_arg_reg=alloc_preg(cfg);/* deref_arg = BOX_TYPE != MONO_GSHAREDVT_BOX_TYPE_VTYPE */EMIT_NEW_BIALU_IMM(cfg,is_deref,OP_ISUB_IMM,deref_arg_reg,ins->dreg,1);MONO_EMIT_NEW_STORE_MEMBASE(cfg,OP_STOREI1_MEMBASE_REG,is_gsharedvt_ins->dreg,i,is_deref->dreg);}Also isn't
deref_argssupposed to be set only for valuetype args, why the check below?
It appears that an argument is being dereferenced if the BOX_TYPE != MONO_GSHAREDVT_BOX_TYPE_VTYPE. However, if the argument is a nullable value type, deref_args [i] is set because mono_class_is_nullable is checked first:
if(MONO_TYPE_IS_REFERENCE(m_class_get_byval_arg(impl_class)))returnGUINT_TO_POINTER(MONO_GSHAREDVT_BOX_TYPE_REF);elseif(mono_class_is_nullable(impl_class))returnGUINT_TO_POINTER(MONO_GSHAREDVT_BOX_TYPE_NULLABLE);elsereturnGUINT_TO_POINTER(MONO_GSHAREDVT_BOX_TYPE_VTYPE);Then, during runtime, a nullable value type is dereferenced, leading to a runtime crash. Perhaps this check (if not nullable vtype) can be moved to the handle_constrained_gsharedvt_call, which might result in larger codegen.
Is there a testcase which fails for this case ?
The fullAOT tests are not currently running on the CI. Once the job is enabled, we will check if this case is already covered. If it is not covered, we will add a runtime test. You can currently verify this by using the following sample: #94467 (comment).
There was a problem hiding this comment.
Would suggest this fix instead:
diff --git a/src/mono/mono/mini/jit-icalls.c b/src/mono/mono/mini/jit-icalls.c
index 21f3252c814..442cb9a65aa 100644
--- a/src/mono/mono/mini/jit-icalls.c
+++ b/src/mono/mono/mini/jit-icalls.c
@@ -1482,7 +1482,7 @@ mono_gsharedvt_constrained_call (gpointer mp, MonoMethod *cmethod, MonoClass *kl
g_assert (fsig->param_count < 16);
memcpy (new_args, args, fsig->param_count * sizeof (gpointer));
for (int i = 0; i < fsig->param_count; ++i) {
- if (deref_args [i])
+ if (deref_args [i] != MONO_GSHAREDVT_BOX_TYPE_VTYPE && deref_args [i] != MONO_GSHAREDVT_BOX_TYPE_NULLABLE)
new_args [i] = *(gpointer*)new_args [i];
}
args = new_args;
diff --git a/src/mono/mono/mini/method-to-ir.c b/src/mono/mono/mini/method-to-ir.c
index 99a11126b62..1f359e31cc6 100644
--- a/src/mono/mono/mini/method-to-ir.c
+++ b/src/mono/mono/mini/method-to-ir.c
@@ -3896,13 +3896,8 @@ handle_constrained_gsharedvt_call (MonoCompile *cfg, MonoMethod *cmethod, MonoMe
int addr_reg;
if (mini_is_gsharedvt_type (fsig->params [i])) {
- MonoInst *is_deref;
- int deref_arg_reg;
ins = mini_emit_get_gsharedvt_info_klass (cfg, mono_class_from_mono_type_internal (fsig->params [i]), MONO_RGCTX_INFO_CLASS_BOX_TYPE);
- deref_arg_reg = alloc_preg (cfg);
- /* deref_arg = BOX_TYPE != MONO_GSHAREDVT_BOX_TYPE_VTYPE */
- EMIT_NEW_BIALU_IMM (cfg, is_deref, OP_ISUB_IMM, deref_arg_reg, ins->dreg, 1);
- MONO_EMIT_NEW_STORE_MEMBASE (cfg, OP_STOREI1_MEMBASE_REG, is_gsharedvt_ins->dreg, i, is_deref->dreg);
+ MONO_EMIT_NEW_STORE_MEMBASE (cfg, OP_STOREI1_MEMBASE_REG, is_gsharedvt_ins->dreg, i, ins->dreg);
} else if (has_gsharedvt) {
MONO_EMIT_NEW_STORE_MEMBASE_IMM (cfg, OP_STOREI1_MEMBASE_IMM, is_gsharedvt_ins->dreg, i, 0);
}
kotlarmilos
commented
Nov 23, 2023
/azp run runtime-extra-platforms |
|
Azure Pipelines successfully started running 1 pipeline(s). |
kotlarmilos
commented
Dec 6, 2023
/azp run runtime-extra-platforms |
|
Azure Pipelines successfully started running 1 pipeline(s). |
kotlarmilos
commented
Dec 8, 2023
/backport to release/8.0-staging |
Started backporting to release/8.0-staging: https://github.com/dotnet/runtime/actions/runs/7140806171 |
vargaz
commented
Dec 8, 2023
Would be nice to have some CI tests before a backport. |
kotlarmilos
commented
Dec 8, 2023
Agreed. Postponing this backport until we enable fullAOT CI tests: #92057. |
kotlarmilos
commented
Apr 24, 2024
/backport to release/8.0-staging |
Started backporting to release/8.0-staging: https://github.com/dotnet/runtime/actions/runs/8815796126 |
@kotlarmilos backporting to release/8.0-staging failed, the patch most likely resulted in conflicts: $ git am --3way --ignore-whitespace --keep-non-patch changes.patch
Applying: [mono] Don't use this_arg in static constrained calls. Don't deref gsharedvt ref arguments if it is a nullable vtype.
Using index info to reconstruct a base tree...
M src/mono/mono/mini/jit-icalls.c
Falling back to patching base and 3-way merge...
Auto-merging src/mono/mono/mini/jit-icalls.c
CONFLICT (content): Merge conflict in src/mono/mono/mini/jit-icalls.c
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 [mono] Don't use this_arg in static constrained calls. Don't deref gsharedvt ref arguments if it is a nullable vtype.
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
Error: The process '/usr/bin/git' failed with exit code 128Please backport manually! |
@kotlarmilos an error occurred while backporting to release/8.0-staging, please check the run log for details! Error: git am failed, most likely due to a merge conflict. |
Description
This PR extends
mono_gsharedvt_constrained_callto handle staticMONO_GSHAREDVT_CONSTRAINT_CALL_TYPE_REFcalls. If the cmethod is a static method,this_argshould beNULL. Also, it skips dereferencing sharedvt ref arguments if they are nullable value types.Fixes#94467