https://issues.dlang.org/show_bug.cgi?id=20939

          Issue ID: 20939
           Summary: sha.digest.sha: increase the speed of SHA256 and
                    SHA512 in non-optimized builds, and bring optimized
                    DMD builds closer to the speed of LDC
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: phobos
          Assignee: nobody@puremagic.com
          Reporter: n8sh.secondary@hotmail.com

Compiled by DMD with no optimizations enabled (a common and even recommended way of using DMD), sha.digest.sha.SHA256 and SHA512 can take up to 26x as much time as they would if compiled with `ldc2 -O3`. This can be substantially improved. This problem is not shared by SHA-1 because it uses an optimized SSE3 implementation.

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