[libc-commits] [PATCH] D106386: [libc] Exclude few unused bits from x86 state for Windows

[Hedin García via Phabricator via libc-commits]

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Windows fenv_t does not include the MXCSR register and
the unused bits at the end of the x87 status. So we
exclude them in our struct definitions to make it
easy to read/write the state. getEnv and setEnv
were also excluded to avoid using MXCSR, but a
forthcoming patch will handle these functions.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D106386

Files:
  libc/utils/FPUtil/x86_64/FEnv.h


Index: libc/utils/FPUtil/x86_64/FEnv.h
===================================================================
--- libc/utils/FPUtil/x86_64/FEnv.h
+++ libc/utils/FPUtil/x86_64/FEnv.h
@@ -91,12 +91,16 @@
   uint16_t StatusWord;
   uint16_t Unused2;
   // TODO: Elaborate the remaining 20 bytes as required.
+  #if !(defined(_WIN32) || defined(_WIN64))
   uint32_t _[5];
+  #endif
 };
 
 struct FPState {
   X87StateDescriptor X87Status;
+  #if !(defined(_WIN32) || defined(_WIN64))
   uint32_t MXCSR;
+  #endif
 };
 
 static_assert(
@@ -346,6 +350,7 @@
   return 0;
 }
 
+#if !(defined(_WIN32) || defined(_WIN64))
 static inline int getEnv(fenv_t *envp) {
   internal::FPState *state = reinterpret_cast<internal::FPState *>(envp);
   internal::getX87StateDescriptor(state->X87Status);
@@ -360,6 +365,7 @@
   internal::writeMXCSR(state->MXCSR);
   return 0;
 }
+#endif
 
 } // namespace fputil
 } // namespace __llvm_libc


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