scripted-diff: rename ABEF_SAVE/CDGH_SAVE to ABCD_SAVE/EFGH_SAVE in SHA-256 ARM intrinsics
What the developer wrote
Authored by jrakibi
scripted-diff: rename ABEF_SAVE/CDGH_SAVE to ABCD_SAVE/EFGH_SAVE in SHA-256 ARM intrinsics
ARM SHA256 intrinsics take state in natural order: ABCD + EFGH
(hash_abcd/hash_efgh). The code already uses that layout, only the
ABEF_SAVE/CDGH_SAVE names were wrong. Rename to ABCD_SAVE/EFGH_SAVE.
No logic change.
Docs: https://developer.arm.com/architectures/instruction-sets/intrinsics/#f:@navigationhierarchiesinstructiongroup=[Cryptography,SHA256]
Fix in original C code (Jeffrey): https://github.com/noloader/SHA-Intrinsics/pull/14
-BEGIN VERIFY SCRIPT-
perl -pi -e 's/\bABEF_SAVE([AB])?\b/ABCD_SAVE$1/g' src/crypto/sha256_arm_shani.cpp
perl -pi -e 's/\bCDGH_SAVE([AB])?\b/EFGH_SAVE$1/g' src/crypto/sha256_arm_shani.cpp
-END VERIFY SCRIPT-
What changed, and why it matters
This is a pure variable-name cleanup in Bitcoin Core's ARM SHA-256 code. The old names (ABEF_SAVE/CDGH_SAVE) were misleading labels; the new names (ABCD_SAVE/EFGH_SAVE) match how ARM's SHA-256 instructions actually order the hash state. No instructions, values, or behavior change.
No security action needed; this is a non-functional readability/correctness-of-naming cleanup.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The commit renames local NEON vector variables in src/crypto/sha256_arm_shani.cpp from ABEF_SAVE/CDGH_SAVE to ABCD_SAVE/EFGH_SAVE. The diff is a scripted rename with identical +14/-14 line counts and no logic changes. STATE0/STATE1 already hold the ABCD/EFGH halves respectively, so the new names are purely cosmetic and align with ARM’s documented vsha256h* intrinsic semantics.
Changed components
src/crypto/sha256_arm_shani.cppInspect captured patch +14 / −14
diff --git a/src/crypto/sha256_arm_shani.cpp b/src/crypto/sha256_arm_shani.cpp
index 2eaa6655..d2290030 100644
--- a/src/crypto/sha256_arm_shani.cpp
+++ b/src/crypto/sha256_arm_shani.cpp
@@ -40,7 +40,7 @@ alignas(uint32x4_t) static constexpr std::array<uint32_t, 64> K =
namespace sha256_arm_shani {
void Transform(uint32_t* s, const unsigned char* chunk, size_t blocks)
{
- uint32x4_t STATE0, STATE1, ABEF_SAVE, CDGH_SAVE;
+ uint32x4_t STATE0, STATE1, ABCD_SAVE, EFGH_SAVE;
uint32x4_t MSG0, MSG1, MSG2, MSG3;
uint32x4_t TMP0, TMP2;
@@ -51,8 +51,8 @@ void Transform(uint32_t* s, const unsigned char* chunk, size_t blocks)
while (blocks--)
{
// Save state
- ABEF_SAVE = STATE0;
- CDGH_SAVE = STATE1;
+ ABCD_SAVE = STATE0;
+ EFGH_SAVE = STATE1;
// Load and convert input chunk to Big Endian
MSG0 = vreinterpretq_u32_u8(vrev32q_u8(vld1q_u8(chunk + 0)));
@@ -186,8 +186,8 @@ void Transform(uint32_t* s, const unsigned char* chunk, size_t blocks)
STATE1 = vsha256h2q_u32(STATE1, TMP2, TMP0);
// Update state
- STATE0 = vaddq_u32(STATE0, ABEF_SAVE);
- STATE1 = vaddq_u32(STATE1, CDGH_SAVE);
+ STATE0 = vaddq_u32(STATE0, ABCD_SAVE);
+ STATE1 = vaddq_u32(STATE1, EFGH_SAVE);
}
// Save final state
@@ -235,7 +235,7 @@ void Transform_2way(unsigned char* output, const unsigned char* input)
/* Padding processed in the 3rd transform (byteswapped). */
alignas(uint32x4_t) static constexpr std::array<uint32_t, 8> FINAL = {0x80000000, 0, 0, 0, 0, 0, 0, 0x100};
- uint32x4_t STATE0A, STATE0B, STATE1A, STATE1B, ABEF_SAVEA, ABEF_SAVEB, CDGH_SAVEA, CDGH_SAVEB;
+ uint32x4_t STATE0A, STATE0B, STATE1A, STATE1B, ABCD_SAVEA, ABCD_SAVEB, EFGH_SAVEA, EFGH_SAVEB;
uint32x4_t MSG0A, MSG0B, MSG1A, MSG1B, MSG2A, MSG2B, MSG3A, MSG3B;
uint32x4_t TMP0A, TMP0B, TMP2A, TMP2B, TMP;
@@ -488,10 +488,10 @@ void Transform_2way(unsigned char* output, const unsigned char* input)
STATE1B = vaddq_u32(STATE1B, TMP);
// Transform 2: Save state
- ABEF_SAVEA = STATE0A;
- ABEF_SAVEB = STATE0B;
- CDGH_SAVEA = STATE1A;
- CDGH_SAVEB = STATE1B;
+ ABCD_SAVEA = STATE0A;
+ ABCD_SAVEB = STATE0B;
+ EFGH_SAVEA = STATE1A;
+ EFGH_SAVEB = STATE1B;
// Transform 2: Rounds 1-4
TMP = vld1q_u32(&MIDS[0]);
@@ -638,10 +638,10 @@ void Transform_2way(unsigned char* output, const unsigned char* input)
STATE1B = vsha256h2q_u32(STATE1B, TMP2B, TMP);
// Transform 2: Update state
- STATE0A = vaddq_u32(STATE0A, ABEF_SAVEA);
- STATE0B = vaddq_u32(STATE0B, ABEF_SAVEB);
- STATE1A = vaddq_u32(STATE1A, CDGH_SAVEA);
- STATE1B = vaddq_u32(STATE1B, CDGH_SAVEB);
+ STATE0A = vaddq_u32(STATE0A, ABCD_SAVEA);
+ STATE0B = vaddq_u32(STATE0B, ABCD_SAVEB);
+ STATE1A = vaddq_u32(STATE1A, EFGH_SAVEA);
+ STATE1B = vaddq_u32(STATE1B, EFGH_SAVEB);
// Transform 3: Pad previous output
MSG0A = STATE0A;
Why this scored 15/100
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