Revert "32-wide manual unroll with 2x compiled... still not as good perf as automatic 48x"

This reverts commit 18b734a6e70e989168c94d051bf2da5c08560790.
This commit is contained in:
Richard Thier 2025-10-01 04:26:32 +02:00
parent 18b734a6e7
commit 100de9bc67

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@ -98,8 +98,8 @@ static inline void threepass_xb(uint32_t *a, uint32_t *buf, int n) noexcept {
// Bottom digit a->buf
// right-to-left to ensure already sorted digits order we keep for iterations
#pragma GCC unroll 2
for(i = n; i >= 32; i -= 32) {
#pragma GCC unroll 3
for(i = n; i >= 16; i -= 16) {
// Prefetch the NEXT block (not current) at optimal distance
if (i > 17) { // Ensure we don't prefetch out of bounds
__builtin_prefetch(&a[i - 17]);
@ -111,57 +111,25 @@ static inline void threepass_xb(uint32_t *a, uint32_t *buf, int n) noexcept {
__builtin_prefetch(&a[i - 17*3]);
}
// Process 32 elements in reverse order
auto num31 = a[i - 1];
auto num30 = a[i - 2];
auto num29 = a[i - 3];
auto num28 = a[i - 4];
auto num27 = a[i - 5];
auto num26 = a[i - 6];
auto num25 = a[i - 7];
auto num24 = a[i - 8];
auto num23 = a[i - 9];
auto num22 = a[i - 10];
auto num21 = a[i - 11];
auto num20 = a[i - 12];
auto num19 = a[i - 13];
auto num18 = a[i - 14];
auto num17 = a[i - 15];
auto num16 = a[i - 16];
auto num15 = a[i - 17];
auto num14 = a[i - 18];
auto num13 = a[i - 19];
auto num12 = a[i - 20];
auto num11 = a[i - 21];
auto num10 = a[i - 22];
auto num9 = a[i - 23];
auto num8 = a[i - 24];
auto num7 = a[i - 25];
auto num6 = a[i - 26];
auto num5 = a[i - 27];
auto num4 = a[i - 28];
auto num3 = a[i - 29];
auto num2 = a[i - 30];
auto num1 = a[i - 31];
auto num0 = a[i - 32];
// Process 16 elements in reverse order
auto num15 = a[i - 1];
auto num14 = a[i - 2];
auto num13 = a[i - 3];
auto num12 = a[i - 4];
auto num11 = a[i - 5];
auto num10 = a[i - 6];
auto num9 = a[i - 7];
auto num8 = a[i - 8];
auto num7 = a[i - 9];
auto num6 = a[i - 10];
auto num5 = a[i - 11];
auto num4 = a[i - 12];
auto num3 = a[i - 13];
auto num2 = a[i - 14];
auto num1 = a[i - 15];
auto num0 = a[i - 16];
// Process all 32 elements (bucket logic here)
tpxb_process_element(num31, buf, bucket3, shr3, mask3);
tpxb_process_element(num30, buf, bucket3, shr3, mask3);
tpxb_process_element(num29, buf, bucket3, shr3, mask3);
tpxb_process_element(num28, buf, bucket3, shr3, mask3);
tpxb_process_element(num27, buf, bucket3, shr3, mask3);
tpxb_process_element(num26, buf, bucket3, shr3, mask3);
tpxb_process_element(num25, buf, bucket3, shr3, mask3);
tpxb_process_element(num24, buf, bucket3, shr3, mask3);
tpxb_process_element(num23, buf, bucket3, shr3, mask3);
tpxb_process_element(num22, buf, bucket3, shr3, mask3);
tpxb_process_element(num21, buf, bucket3, shr3, mask3);
tpxb_process_element(num20, buf, bucket3, shr3, mask3);
tpxb_process_element(num19, buf, bucket3, shr3, mask3);
tpxb_process_element(num18, buf, bucket3, shr3, mask3);
tpxb_process_element(num17, buf, bucket3, shr3, mask3);
tpxb_process_element(num16, buf, bucket3, shr3, mask3);
// Process all 16 elements (your bucket logic here)
tpxb_process_element(num15, buf, bucket3, shr3, mask3);
tpxb_process_element(num14, buf, bucket3, shr3, mask3);
tpxb_process_element(num13, buf, bucket3, shr3, mask3);
@ -179,7 +147,7 @@ static inline void threepass_xb(uint32_t *a, uint32_t *buf, int n) noexcept {
tpxb_process_element(num1, buf, bucket3, shr3, mask3);
tpxb_process_element(num0, buf, bucket3, shr3, mask3);
}
// Handle remainder
// Handle remainder (less than 16 elements)
for(uint32_t j = i; j > 0; --j) {
auto num = a[j - 1];
auto bkeyni = (num >> shr3) & mask3;
@ -189,8 +157,8 @@ static inline void threepass_xb(uint32_t *a, uint32_t *buf, int n) noexcept {
// Mid digit buf->a
// right-to-left to ensure already sorted digits order we keep for iterations
#pragma GCC unroll 2
for(i = n; i >= 32; i -= 32) {
#pragma GCC unroll 3
for(i = n; i >= 16; i -= 16) {
// Prefetch the NEXT block (not current) at optimal distance
if (i > 17) { // Ensure we don't prefetch out of bounds
__builtin_prefetch(&buf[i - 17]);
@ -202,57 +170,25 @@ static inline void threepass_xb(uint32_t *a, uint32_t *buf, int n) noexcept {
__builtin_prefetch(&buf[i - 17*3]);
}
// Process 32 elements in reverse order
auto num31 = buf[i - 1];
auto num30 = buf[i - 2];
auto num29 = buf[i - 3];
auto num28 = buf[i - 4];
auto num27 = buf[i - 5];
auto num26 = buf[i - 6];
auto num25 = buf[i - 7];
auto num24 = buf[i - 8];
auto num23 = buf[i - 9];
auto num22 = buf[i - 10];
auto num21 = buf[i - 11];
auto num20 = buf[i - 12];
auto num19 = buf[i - 13];
auto num18 = buf[i - 14];
auto num17 = buf[i - 15];
auto num16 = buf[i - 16];
auto num15 = buf[i - 17];
auto num14 = buf[i - 18];
auto num13 = buf[i - 19];
auto num12 = buf[i - 20];
auto num11 = buf[i - 21];
auto num10 = buf[i - 22];
auto num9 = buf[i - 23];
auto num8 = buf[i - 24];
auto num7 = buf[i - 25];
auto num6 = buf[i - 26];
auto num5 = buf[i - 27];
auto num4 = buf[i - 28];
auto num3 = buf[i - 29];
auto num2 = buf[i - 30];
auto num1 = buf[i - 31];
auto num0 = buf[i - 32];
// Process 16 elements in reverse order
auto num15 = buf[i - 1];
auto num14 = buf[i - 2];
auto num13 = buf[i - 3];
auto num12 = buf[i - 4];
auto num11 = buf[i - 5];
auto num10 = buf[i - 6];
auto num9 = buf[i - 7];
auto num8 = buf[i - 8];
auto num7 = buf[i - 9];
auto num6 = buf[i - 10];
auto num5 = buf[i - 11];
auto num4 = buf[i - 12];
auto num3 = buf[i - 13];
auto num2 = buf[i - 14];
auto num1 = buf[i - 15];
auto num0 = buf[i - 16];
// Process all 32 elements (bucket logic here)
tpxb_process_element(num31, a, bucket2, shr2, mask2);
tpxb_process_element(num30, a, bucket2, shr2, mask2);
tpxb_process_element(num29, a, bucket2, shr2, mask2);
tpxb_process_element(num28, a, bucket2, shr2, mask2);
tpxb_process_element(num27, a, bucket2, shr2, mask2);
tpxb_process_element(num26, a, bucket2, shr2, mask2);
tpxb_process_element(num25, a, bucket2, shr2, mask2);
tpxb_process_element(num24, a, bucket2, shr2, mask2);
tpxb_process_element(num23, a, bucket2, shr2, mask2);
tpxb_process_element(num22, a, bucket2, shr2, mask2);
tpxb_process_element(num21, a, bucket2, shr2, mask2);
tpxb_process_element(num20, a, bucket2, shr2, mask2);
tpxb_process_element(num19, a, bucket2, shr2, mask2);
tpxb_process_element(num18, a, bucket2, shr2, mask2);
tpxb_process_element(num17, a, bucket2, shr2, mask2);
tpxb_process_element(num16, a, bucket2, shr2, mask2);
// Process all 16 elements (your bucket logic here)
tpxb_process_element(num15, a, bucket2, shr2, mask2);
tpxb_process_element(num14, a, bucket2, shr2, mask2);
tpxb_process_element(num13, a, bucket2, shr2, mask2);
@ -270,7 +206,7 @@ static inline void threepass_xb(uint32_t *a, uint32_t *buf, int n) noexcept {
tpxb_process_element(num1, a, bucket2, shr2, mask2);
tpxb_process_element(num0, a, bucket2, shr2, mask2);
}
// Handle remainder
// Handle remainder (less than 16 elements)
for(uint32_t j = i; j > 0; --j) {
auto num = buf[j - 1];
auto bkeyni = (num >> shr2) & mask2;
@ -279,8 +215,8 @@ static inline void threepass_xb(uint32_t *a, uint32_t *buf, int n) noexcept {
}
// Top digit a->buf
// right-to-left to ensure already sorted digits order we keep for iterations
#pragma GCC unroll 2
for(i = n; i >= 32; i -= 32) {
#pragma GCC unroll 3
for(i = n; i >= 16; i -= 16) {
// Prefetch the NEXT block (not current) at optimal distance
if (i > 17) { // Ensure we don't prefetch out of bounds
__builtin_prefetch(&a[i - 17]);
@ -292,57 +228,25 @@ static inline void threepass_xb(uint32_t *a, uint32_t *buf, int n) noexcept {
__builtin_prefetch(&a[i - 17*3]);
}
// Process 32 elements in reverse order
auto num31 = a[i - 1];
auto num30 = a[i - 2];
auto num29 = a[i - 3];
auto num28 = a[i - 4];
auto num27 = a[i - 5];
auto num26 = a[i - 6];
auto num25 = a[i - 7];
auto num24 = a[i - 8];
auto num23 = a[i - 9];
auto num22 = a[i - 10];
auto num21 = a[i - 11];
auto num20 = a[i - 12];
auto num19 = a[i - 13];
auto num18 = a[i - 14];
auto num17 = a[i - 15];
auto num16 = a[i - 16];
auto num15 = a[i - 17];
auto num14 = a[i - 18];
auto num13 = a[i - 19];
auto num12 = a[i - 20];
auto num11 = a[i - 21];
auto num10 = a[i - 22];
auto num9 = a[i - 23];
auto num8 = a[i - 24];
auto num7 = a[i - 25];
auto num6 = a[i - 26];
auto num5 = a[i - 27];
auto num4 = a[i - 28];
auto num3 = a[i - 29];
auto num2 = a[i - 30];
auto num1 = a[i - 31];
auto num0 = a[i - 32];
// Process 16 elements in reverse order
auto num15 = a[i - 1];
auto num14 = a[i - 2];
auto num13 = a[i - 3];
auto num12 = a[i - 4];
auto num11 = a[i - 5];
auto num10 = a[i - 6];
auto num9 = a[i - 7];
auto num8 = a[i - 8];
auto num7 = a[i - 9];
auto num6 = a[i - 10];
auto num5 = a[i - 11];
auto num4 = a[i - 12];
auto num3 = a[i - 13];
auto num2 = a[i - 14];
auto num1 = a[i - 15];
auto num0 = a[i - 16];
// Process all 32 elements (your bucket logic here)
tpxb_process_element(num31, buf, bucket1, shr1, mask1);
tpxb_process_element(num30, buf, bucket1, shr1, mask1);
tpxb_process_element(num29, buf, bucket1, shr1, mask1);
tpxb_process_element(num28, buf, bucket1, shr1, mask1);
tpxb_process_element(num27, buf, bucket1, shr1, mask1);
tpxb_process_element(num26, buf, bucket1, shr1, mask1);
tpxb_process_element(num25, buf, bucket1, shr1, mask1);
tpxb_process_element(num24, buf, bucket1, shr1, mask1);
tpxb_process_element(num23, buf, bucket1, shr1, mask1);
tpxb_process_element(num22, buf, bucket1, shr1, mask1);
tpxb_process_element(num21, buf, bucket1, shr1, mask1);
tpxb_process_element(num20, buf, bucket1, shr1, mask1);
tpxb_process_element(num19, buf, bucket1, shr1, mask1);
tpxb_process_element(num18, buf, bucket1, shr1, mask1);
tpxb_process_element(num17, buf, bucket1, shr1, mask1);
tpxb_process_element(num16, buf, bucket1, shr1, mask1);
// Process all 16 elements (your bucket logic here)
tpxb_process_element(num15, buf, bucket1, shr1, mask1);
tpxb_process_element(num14, buf, bucket1, shr1, mask1);
tpxb_process_element(num13, buf, bucket1, shr1, mask1);
@ -360,7 +264,7 @@ static inline void threepass_xb(uint32_t *a, uint32_t *buf, int n) noexcept {
tpxb_process_element(num1, buf, bucket1, shr1, mask1);
tpxb_process_element(num0, buf, bucket1, shr1, mask1);
}
// Handle remainder
// Handle remainder (less than 16 elements)
for(uint32_t j = i; j > 0; --j) {
auto num = a[j - 1];
auto bkeyni = (num >> shr1) & mask1;