From c909a7aa6e2aaa4fb7468f8d90b370a5862fe515 Mon Sep 17 00:00:00 2001
From: Josh Haberman <jhaberman@gmail.com>
Date: Tue, 14 Mar 2017 17:34:09 -0700
Subject: Deleted some dead code related to varint decoding.

---
 upb/pb/varint.c     | 51 ---------------------------------------------------
 upb/pb/varint.int.h | 14 --------------
 2 files changed, 65 deletions(-)

(limited to 'upb')

diff --git a/upb/pb/varint.c b/upb/pb/varint.c
index 25cdd81..90f58a1 100644
--- a/upb/pb/varint.c
+++ b/upb/pb/varint.c
@@ -72,54 +72,3 @@ done:
   r.p = p;
   return r;
 }
-
-/* Given an encoded varint v, returns an integer with a single bit set that
- * indicates the end of the varint.  Subtracting one from this value will
- * yield a mask that leaves only bits that are part of the varint.  Returns
- * 0 if the varint is unterminated. */
-static uint64_t upb_get_vstopbit(uint64_t v) {
-  uint64_t cbits = v | 0x7f7f7f7f7f7f7f7fULL;
-  return ~cbits & (cbits+1);
-}
-
-/* A branchless decoder.  Credit to Pascal Massimino for the bit-twiddling. */
-upb_decoderet upb_vdecode_max8_massimino(upb_decoderet r) {
-  uint64_t b;
-  uint64_t stop_bit;
-  upb_decoderet my_r;
-  memcpy(&b, r.p, sizeof(b));
-  stop_bit = upb_get_vstopbit(b);
-  b =  (b & 0x7f7f7f7f7f7f7f7fULL) & (stop_bit - 1);
-  b +=       b & 0x007f007f007f007fULL;
-  b +=  3 * (b & 0x0000ffff0000ffffULL);
-  b += 15 * (b & 0x00000000ffffffffULL);
-  if (stop_bit == 0) {
-    /* Error: unterminated varint. */
-    upb_decoderet err_r = {(void*)0, 0};
-    return err_r;
-  }
-  my_r = upb_decoderet_make(r.p + ((__builtin_ctzll(stop_bit) + 1) / 8),
-                            r.val | (b << 7));
-  return my_r;
-}
-
-/* A branchless decoder.  Credit to Daniel Wright for the bit-twiddling. */
-upb_decoderet upb_vdecode_max8_wright(upb_decoderet r) {
-  uint64_t b;
-  uint64_t stop_bit;
-  upb_decoderet my_r;
-  memcpy(&b, r.p, sizeof(b));
-  stop_bit = upb_get_vstopbit(b);
-  b &= (stop_bit - 1);
-  b = ((b & 0x7f007f007f007f00ULL) >> 1) | (b & 0x007f007f007f007fULL);
-  b = ((b & 0xffff0000ffff0000ULL) >> 2) | (b & 0x0000ffff0000ffffULL);
-  b = ((b & 0xffffffff00000000ULL) >> 4) | (b & 0x00000000ffffffffULL);
-  if (stop_bit == 0) {
-    /* Error: unterminated varint. */
-    upb_decoderet err_r = {(void*)0, 0};
-    return err_r;
-  }
-  my_r = upb_decoderet_make(r.p + ((__builtin_ctzll(stop_bit) + 1) / 8),
-                            r.val | (b << 14));
-  return my_r;
-}
diff --git a/upb/pb/varint.int.h b/upb/pb/varint.int.h
index c8d4929..3ef84fb 100644
--- a/upb/pb/varint.int.h
+++ b/upb/pb/varint.int.h
@@ -62,16 +62,8 @@ UPB_INLINE upb_decoderet upb_decoderet_make(const char *p, uint64_t val) {
   return ret;
 }
 
-/* Four functions for decoding a varint of at most eight bytes.  They are all
- * functionally identical, but are implemented in different ways and likely have
- * different performance profiles.  We keep them around for performance testing.
- *
- * Note that these functions may not read byte-by-byte, so they must not be used
- * unless there are at least eight bytes left in the buffer! */
 upb_decoderet upb_vdecode_max8_branch32(upb_decoderet r);
 upb_decoderet upb_vdecode_max8_branch64(upb_decoderet r);
-upb_decoderet upb_vdecode_max8_wright(upb_decoderet r);
-upb_decoderet upb_vdecode_max8_massimino(upb_decoderet r);
 
 /* Template for a function that checks the first two bytes with branching
  * and dispatches 2-10 bytes with a separate function.  Note that this may read
@@ -96,8 +88,6 @@ UPB_INLINE upb_decoderet upb_vdecode_check2_ ## name(const char *_p) {         \
 
 UPB_VARINT_DECODER_CHECK2(branch32, upb_vdecode_max8_branch32)
 UPB_VARINT_DECODER_CHECK2(branch64, upb_vdecode_max8_branch64)
-UPB_VARINT_DECODER_CHECK2(wright, upb_vdecode_max8_wright)
-UPB_VARINT_DECODER_CHECK2(massimino, upb_vdecode_max8_massimino)
 #undef UPB_VARINT_DECODER_CHECK2
 
 /* Our canonical functions for decoding varints, based on the currently
@@ -109,10 +99,6 @@ UPB_INLINE upb_decoderet upb_vdecode_fast(const char *p) {
     return upb_vdecode_check2_branch32(p);
 }
 
-UPB_INLINE upb_decoderet upb_vdecode_max8_fast(upb_decoderet r) {
-  return upb_vdecode_max8_massimino(r);
-}
-
 
 /* Encoding *******************************************************************/
 
-- 
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