Ensure that math calls into the CRT are tracked as needing vzeroupper #112011
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| // A few other special cases exist that can't be found by signature alone, so we handle | ||
| // those explicitly here instead. | ||
| needsVzeroupper = IsHelperCall(comp, CORINFO_HELP_BULK_WRITEBARRIER); | ||
| break; |
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The signature only needs to be checked when needsVzeroupper is still false: checkSignature = !needsVzeroupper.
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The root issue was that
GenTreeCall::NeedsVzeroupperwas only looking atIsPInvoke()methods, while calls likeMath.Sinare represented as regularCT_USERCALL, thus we lost track of the fact that this was not actually in managed.This then resolves #111016 by ensuring that we correctly mark such calls as being "special" (via
GTF_CALL_M_SPECIAL_INTRINSIC) which then allows us to decide to do the additional signature checking and determine that avzeroupperis needed.If any of these calls are later moved to managed, then we can avoid the
vzeroupperby not marking these particular cases as "special". This already applies to cases likeSqrtwhich are never rewritten back as user calls or cases like Max where we know the fallback is in managed, rather than into the C runtime.