[ARM] Do not generate Tag_DIV_use=AllowDIVExt when hardware div is non-optional:...

[oota-llvm.git] / include / llvm / Support / ARMBuildAttributes.h

diff --git a/include/llvm/Support/ARMBuildAttributes.h b/include/llvm/Support/ARMBuildAttributes.h
index ef52ffba0859673e83900a24263559da597955b8..69732fc041e7c3a2971ce2cef263ccf8d55b72ee 100644 (file)
--- a/include/llvm/Support/ARMBuildAttributes.h
+++ b/include/llvm/Support/ARMBuildAttributes.h
@@ -168,9 +168,11 @@ enum {
   AllowMP = 1, // Allow use of MP extensions
 
   // Tag_DIV_use, (=44), uleb128
+  // Note: AllowDIVExt must be emitted if and only if the permission to use
+  // hardware divide cannot be conveyed using AllowDIVIfExists or DisallowDIV
   AllowDIVIfExists = 0, // Allow hardware divide if available in arch, or no
                         // info exists.
-  DisallowDIV = 1,      // Hardware divide explicitly disallowed
+  DisallowDIV = 1,      // Hardware divide explicitly disallowed.
   AllowDIVExt = 2,      // Allow hardware divide as optional architecture
                         // extension above the base arch specified by
                         // Tag_CPU_arch and Tag_CPU_arch_profile.