Merging r353411:

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r353411 | erichkeane | 2019-02-07 16:14:11 +0100 (Thu, 07 Feb 2019) | 7 lines

Fix r350643 to limit COFF emission to <= 32 BYTES instead of BITS.

The patch in r350643 incorrectly sets the COFF emission based on bits
instead of bytes. This patch converts the 32 via CharUnits to bits to
compare the correct values.

Change-Id: Icf38a16470ad5ae3531374969c033557ddb0d323
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llvm-svn: 353825

Author: zmodem

clang/lib/CodeGen/CodeGenModule.cpp

@@ -3762,13 +3762,15 @@ static bool isVarDeclStrongDefinition(const ASTContext &Context,
     }
   }
 
-  // Microsoft's link.exe doesn't support alignments greater than 32 for common
-  // symbols, so symbols with greater alignment requirements cannot be common.
+  // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
+  // common symbols, so symbols with greater alignment requirements cannot be
+  // common.
   // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
   // alignments for common symbols via the aligncomm directive, so this
   // restriction only applies to MSVC environments.
   if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
-      Context.getTypeAlignIfKnown(D->getType()) > 32)
+      Context.getTypeAlignIfKnown(D->getType()) >
+          Context.toBits(CharUnits::fromQuantity(32)))
     return true;
 
   return false;

clang/test/CodeGen/microsoft-no-common-align.c

@@ -6,3 +6,6 @@ TooLargeAlignment TooBig;
 // CHECK: @TooBig = dso_local global <16 x float>  zeroinitializer, align 64
 NormalAlignment JustRight;
 // CHECK: @JustRight = common dso_local global <1 x float>  zeroinitializer, align 4
+
+TooLargeAlignment *IsAPointer;
+// CHECK: @IsAPointer = common dso_local global <16 x float>* null, align 8