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Problem 694
Cube-full divisors: S(10^18) via DFS over p^3 | n cube-fulls. Ported from native C to pure Flow.
View problem on Project Euler
Performance comparison
Metric Our solution Best known
Time complexity O(n log n)O(n log log n)
Space complexity O(n)O(n)
Approach Flow solution Sieve-based divisor sums
Verdict Suboptimal
Flow source
# Project Euler 694
# Cube-full divisors: S(10^18) via DFS over p^3 | n cube-fulls.
# Ported from native C to pure Flow.
extern {
function calloc(n: i64, size: i64) -> ptr<void>
function free(p: ptr<void>) -> void
function cbrt(x: f64) -> f64
}
let mut N: i64 = 0
let mut primes: ptr<i64> = null
let mut pc: i64 = 0
function generate(curr0: i64, idx: i64) -> i64 {
let mut total: i64 = 0
let p: i64 = primes[idx]
if curr0 > N / (p * p * p) {
return 0
}
let mut curr: i64 = curr0 * (p * p * p)
while curr <= N {
total = total + N / curr
for j in (idx + 1)..pc {
let t: i64 = generate(curr, j)
if t == 0 {
break
}
total = total + t
}
if curr > N / p {
break
}
curr = curr * p
}
return total
}
function main() -> i32 {
N = 1000000000000000000
let lim: i64 = (cbrt(N as f64) + 2.0) as i64
let sieve: ptr<i8> = calloc(lim + 1, 1) as ptr<i8>
primes = calloc(lim, 8) as ptr<i64>
pc = 0
let mut i: i64 = 2
while i <= lim {
if sieve[i] == 0 {
primes[pc] = i
pc = pc + 1
let mut j: i64 = i * i
while j <= lim {
sieve[j] = 1
j = j + i
}
}
i = i + 1
}
let mut ans: i64 = N
for i in 0..pc {
ans = ans + generate(1, i)
}
free(sieve as ptr<void>)
free(primes as ptr<void>)
printf("%lld\n", ans)
return 0
}
Generated C
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* Flow runtime helpers */
typedef struct flow_temp_node { struct flow_temp_node* next; } flow_temp_node;
static flow_temp_node* flow_temp_head = NULL;
static int flow_temp_atexit_set = 0;
__attribute__((unused)) static void flow_temp_free_all(void) {
while (flow_temp_head) {
flow_temp_node* n = flow_temp_head;
flow_temp_head = n->next;
free(n);
}
}
__attribute__((unused)) static void* flow_temp_alloc(size_t nbytes) {
flow_temp_node* node = (flow_temp_node*)malloc(sizeof(flow_temp_node) + nbytes);
if (!node) return NULL;
node->next = flow_temp_head;
flow_temp_head = node;
if (!flow_temp_atexit_set) {
flow_temp_atexit_set = 1;
atexit(flow_temp_free_all);
}
return (void*)(node + 1);
}
#ifndef FLOW_DIAG
#define FLOW_DIAG(msg) fprintf(stderr, "%s", (msg))
#endif
#ifndef FLOW_LOG
#define FLOW_LOG(fmt, ...) printf(fmt, __VA_ARGS__)
#endif
#ifndef FLOW_LOG_EMPTY
#define FLOW_LOG_EMPTY(fmt) printf(fmt)
#endif
static char* flow_strcat(const char* a, const char* b) {
size_t la = strlen(a ? a : ""), lb = strlen(b ? b : "");
char* r = (char*)flow_temp_alloc(la + lb + 1);
if (!r) return NULL;
if (la) memcpy(r, a, la);
if (lb) memcpy(r + la, b, lb);
r[la + lb] = '\0';
return r;
}
#define __flow_in_arr(arr, val) __extension__ ({ \
int _found = 0; \
size_t _n = sizeof(arr)/sizeof((arr)[0]); \
for (size_t _i = 0; _i < _n; _i++) { \
if ((arr)[_i] == (val)) { _found = 1; break; } \
} _found; })
/* Unified fault handler (MISRA #279) — override with -DFLOW_FAULT_HANDLER=fn */
#ifndef FLOW_FAULT_HANDLER
__attribute__((unused)) static inline void flow_fault_handler(const char* msg) {
fprintf(stderr, "flow: %s\n", msg ? msg : "fault");
abort();
#if defined(__GNUC__) || defined(__clang__)
__builtin_unreachable();
#endif
}
#else
#define flow_fault_handler FLOW_FAULT_HANDLER
#endif
#define flow_div_by_zero_handler() flow_fault_handler("division by zero")
#define flow_shift_ub_handler() flow_fault_handler("invalid shift (amount out of range or left-shift of negative)")
#ifndef FLOW_CHECKED_DIV
#define FLOW_CHECKED_DIV(L, R) (((R) != 0) ? ((L) / (R)) : (flow_div_by_zero_handler(), (L) * 0))
#endif
#ifndef FLOW_CHECKED_MOD
#define FLOW_CHECKED_MOD(L, R) (((R) != 0) ? ((L) % (R)) : (flow_div_by_zero_handler(), (L) * 0))
#endif
#ifndef FLOW_CHECKED_SHL
#define FLOW_CHECKED_SHL(L, R) ((((R) >= 0) && ((unsigned long long)(R) < (sizeof(L) * 8ull)) && ((L) >= 0)) ? ((L) << (R)) : (flow_shift_ub_handler(), (L) * 0))
#endif
#ifndef FLOW_CHECKED_SHR
#define FLOW_CHECKED_SHR(L, R) ((((R) >= 0) && ((unsigned long long)(R) < (sizeof(L) * 8ull))) ? ((L) >> (R)) : (flow_shift_ub_handler(), (L) * 0))
#endif
#include <math.h>
void* _ui_state = NULL;
static inline float i32_to_f32(int32_t v) { return (float)v; }
/* Host stub for @gpu kernels (device codegen replaces this). */
static inline int32_t gpu_thread_id(void) { return 0; }
double cbrt(double x);
int64_t generate_i64_i64(int64_t curr0, int64_t idx);
int32_t main(void);
/* Module statics */
static int64_t N = 0;
static int64_t* primes = NULL;
static int64_t pc = 0;
int64_t generate_i64_i64(int64_t curr0, int64_t idx) {
int64_t total = 0;
int64_t p = primes[idx];
if (curr0 > FLOW_CHECKED_DIV((N), (((p * p) * p)))) {
return 0;
}
int64_t curr = (curr0 * ((p * p) * p));
while (curr <= N) {
total = (total + FLOW_CHECKED_DIV((N), (curr)));
int32_t __flow_step_1 = 1;
for (int32_t j = (idx + 1); ((idx + 1) <= pc) ? j < pc : j > pc; j += ((idx + 1) <= pc) ? 1 : -1) {
int64_t t = generate_i64_i64(curr, j);
if (t == 0) {
break;
}
total = (total + t);
}
if (curr > FLOW_CHECKED_DIV((N), (p))) {
break;
}
curr = (curr * p);
}
return total;
}
int32_t main(void) {
N = 1000000000000000000;
int64_t lim = ((int64_t)((cbrt(((double)(N))) + 2.0)));
int8_t* sieve = (int8_t*)(((int8_t*)(calloc((lim + 1), 1))));
primes = ((int64_t*)(calloc(lim, 8)));
pc = 0;
int64_t i = 2;
while (i <= lim) {
if (sieve[i] == 0) {
primes[pc] = i;
pc = (pc + 1);
int64_t j = (i * i);
while (j <= lim) {
sieve[j] = 1;
j = (j + i);
}
}
i = (i + 1);
}
int64_t ans = N;
int32_t __flow_step_2 = 1;
for (int32_t i = 0; (0 <= pc) ? i < pc : i > pc; i += (0 <= pc) ? 1 : -1) {
ans = (ans + generate_i64_i64(1, i));
}
free(((void*)(sieve)));
free(((void*)(primes)));
printf("%lld\n", ans);
return 0;
}
Generated MLIR
module {
llvm.func @printf(!llvm.ptr, ...) -> i32
llvm.mlir.global internal constant @str_0("%lld\n\00") {addr_space = 0 : i32} : !llvm.array<6 x i8>
func.func private @calloc(i64, i64) -> !llvm.ptr
func.func private @free(!llvm.ptr) -> ()
func.func private @cbrt(f64) -> f64
// Module static: N
llvm.mlir.global internal @N(0 : i64) : i64
// Module static: primes
llvm.mlir.global internal @primes() {addr_space = 0 : i32} : !llvm.ptr {
%0 = llvm.mlir.zero : !llvm.ptr
llvm.return %0 : !llvm.ptr
}
// Module static: pc
llvm.mlir.global internal @pc(0 : i64) : i64
func.func @generate(%arg0: i64, %arg1: i64) -> i64 {
%1 = arith.constant 0 : i32
%2 = arith.extsi %1 : i32 to i64
%3 = llvm.mlir.constant(1 : i64) : i64
%4 = llvm.alloca %3 x i64 : (i64) -> !llvm.ptr
llvm.store %2, %4 : i64, !llvm.ptr
%6 = llvm.mlir.addressof @primes : !llvm.ptr
%7 = llvm.load %6 : !llvm.ptr -> !llvm.ptr
%8 = llvm.getelementptr %7[%arg1] : (!llvm.ptr, i64) -> !llvm.ptr, i64
%5 = llvm.load %8 : !llvm.ptr -> i64
%9 = llvm.mlir.addressof @N : !llvm.ptr
%10 = llvm.load %9 : !llvm.ptr -> i64
%11 = arith.muli %5, %5 : i64
%12 = arith.muli %11, %5 : i64
%13 = arith.divsi %10, %12 : i64
%14 = arith.cmpi sgt, %arg0, %13 : i64
cf.cond_br %14, ^bb0, ^bb1
^bb0:
%15 = arith.constant 0 : i32
%16 = arith.extsi %15 : i32 to i64
func.return %16 : i64
^bb1:
cf.br ^bb2
^bb2:
%17 = arith.muli %5, %5 : i64
%18 = arith.muli %17, %5 : i64
%19 = arith.muli %arg0, %18 : i64
%20 = llvm.mlir.constant(1 : i64) : i64
%21 = llvm.alloca %20 x i64 : (i64) -> !llvm.ptr
llvm.store %19, %21 : i64, !llvm.ptr
cf.br ^bb3
^bb3:
%22 = llvm.load %21 : !llvm.ptr -> i64
%23 = llvm.mlir.addressof @N : !llvm.ptr
%24 = llvm.load %23 : !llvm.ptr -> i64
%25 = arith.cmpi sle, %22, %24 : i64
cf.cond_br %25, ^bb4, ^bb5
^bb4:
%26 = llvm.load %4 : !llvm.ptr -> i64
%27 = llvm.mlir.addressof @N : !llvm.ptr
%28 = llvm.load %27 : !llvm.ptr -> i64
%29 = llvm.load %21 : !llvm.ptr -> i64
%30 = arith.divsi %28, %29 : i64
%31 = arith.addi %26, %30 : i64
llvm.store %31, %4 : i64, !llvm.ptr
%32 = arith.constant 1 : i32
%34 = arith.extsi %32 : i32 to i64
%33 = arith.addi %arg1, %34 : i64
%35 = llvm.mlir.addressof @pc : !llvm.ptr
%36 = llvm.load %35 : !llvm.ptr -> i64
%37 = arith.index_cast %33 : i32 to index
%38 = arith.index_cast %36 : i32 to index
%40 = arith.constant 1 : index
%41 = arith.constant -1 : index
%42 = arith.cmpi sle, %37, %38 : index
%39 = arith.select %42, %40, %41 : index
cf.br ^bb6(%37 : index)
^bb6(%43: index):
%44 = arith.cmpi slt, %43, %38 : index
%45 = arith.cmpi sgt, %43, %38 : index
%46 = arith.select %42, %44, %45 : i1
cf.cond_br %46, ^bb7(%43 : index), ^bb8(%43 : index)
^bb7(%47: index):
%49 = llvm.load %21 : !llvm.ptr -> i64
%50 = arith.index_cast %47 : index to i64
%48 = func.call @generate(%49, %50) : (i64, i64) -> i64
%51 = arith.constant 0 : i32
%53 = arith.extsi %51 : i32 to i64
%52 = arith.cmpi eq, %48, %53 : i64
cf.cond_br %52, ^bb9, ^bb10
^bb9:
cf.br ^bb8(%47 : index)
^bb10:
cf.br ^bb11
^bb11:
%54 = llvm.load %4 : !llvm.ptr -> i64
%55 = arith.addi %54, %48 : i64
llvm.store %55, %4 : i64, !llvm.ptr
%56 = arith.addi %47, %39 : index
cf.br ^bb6(%56 : index)
^bb8(%57: index):
%58 = llvm.load %21 : !llvm.ptr -> i64
%59 = llvm.mlir.addressof @N : !llvm.ptr
%60 = llvm.load %59 : !llvm.ptr -> i64
%61 = arith.divsi %60, %5 : i64
%62 = arith.cmpi sgt, %58, %61 : i64
cf.cond_br %62, ^bb12, ^bb13
^bb12:
cf.br ^bb5
^bb13:
cf.br ^bb14
^bb14:
%63 = llvm.load %21 : !llvm.ptr -> i64
%64 = arith.muli %63, %5 : i64
llvm.store %64, %21 : i64, !llvm.ptr
cf.br ^bb3
^bb5:
%65 = llvm.load %4 : !llvm.ptr -> i64
func.return %65 : i64
}
func.func @main() -> i32 {
%66 = arith.constant 999999995705032704 : i32
%67 = arith.extsi %66 : i32 to i64
%68 = llvm.mlir.addressof @N : !llvm.ptr
llvm.store %67, %68 : i64, !llvm.ptr
%70 = llvm.mlir.addressof @N : !llvm.ptr
%71 = llvm.load %70 : !llvm.ptr -> i64
%72 = arith.sitofp %71 : i64 to f64
%69 = func.call @cbrt(%72) : (f64) -> f64
%73 = arith.constant 2.0 : f32
%75 = arith.extf %73 : f32 to f64
%74 = arith.addf %69, %75 : f64
%76 = arith.fptosi %74 : f64 to i64
%78 = arith.constant 1 : i32
%80 = arith.extsi %78 : i32 to i64
%79 = arith.addi %76, %80 : i64
%81 = arith.constant 1 : i32
%82 = arith.extsi %81 : i32 to i64
%77 = func.call @calloc(%79, %82) : (i64, i64) -> !llvm.ptr
%84 = arith.constant 8 : i32
%85 = arith.extsi %84 : i32 to i64
%83 = func.call @calloc(%76, %85) : (i64, i64) -> !llvm.ptr
%86 = llvm.mlir.addressof @primes : !llvm.ptr
llvm.store %83, %86 : !llvm.ptr, !llvm.ptr
%87 = arith.constant 0 : i32
%88 = arith.extsi %87 : i32 to i64
%89 = llvm.mlir.addressof @pc : !llvm.ptr
llvm.store %88, %89 : i64, !llvm.ptr
%90 = arith.constant 2 : i32
%91 = arith.extsi %90 : i32 to i64
%92 = llvm.mlir.constant(1 : i64) : i64
%93 = llvm.alloca %92 x i64 : (i64) -> !llvm.ptr
llvm.store %91, %93 : i64, !llvm.ptr
cf.br ^bb15
^bb15:
%94 = llvm.load %93 : !llvm.ptr -> i64
%95 = arith.cmpi sle, %94, %76 : i64
cf.cond_br %95, ^bb16, ^bb17
^bb16:
%97 = llvm.load %93 : !llvm.ptr -> i64
%98 = llvm.getelementptr %77[%97] : (!llvm.ptr, i64) -> !llvm.ptr, i8
%96 = llvm.load %98 : !llvm.ptr -> i8
%99 = arith.constant 0 : i32
%101 = arith.extsi %96 : i8 to i32
%100 = arith.cmpi eq, %101, %99 : i32
cf.cond_br %100, ^bb18, ^bb19
^bb18:
%102 = llvm.load %93 : !llvm.ptr -> i64
%103 = llvm.mlir.addressof @primes : !llvm.ptr
%104 = llvm.load %103 : !llvm.ptr -> !llvm.ptr
%105 = llvm.mlir.addressof @pc : !llvm.ptr
%106 = llvm.load %105 : !llvm.ptr -> i64
%107 = llvm.getelementptr %104[%106] : (!llvm.ptr, i64) -> !llvm.ptr, i64
llvm.store %102, %107 : i64, !llvm.ptr
%108 = llvm.mlir.addressof @pc : !llvm.ptr
%109 = llvm.load %108 : !llvm.ptr -> i64
%110 = arith.constant 1 : i32
%112 = arith.extsi %110 : i32 to i64
%111 = arith.addi %109, %112 : i64
%113 = llvm.mlir.addressof @pc : !llvm.ptr
llvm.store %111, %113 : i64, !llvm.ptr
%114 = llvm.load %93 : !llvm.ptr -> i64
%115 = llvm.load %93 : !llvm.ptr -> i64
%116 = arith.muli %114, %115 : i64
%117 = llvm.mlir.constant(1 : i64) : i64
%118 = llvm.alloca %117 x i64 : (i64) -> !llvm.ptr
llvm.store %116, %118 : i64, !llvm.ptr
cf.br ^bb21
^bb21:
%119 = llvm.load %118 : !llvm.ptr -> i64
%120 = arith.cmpi sle, %119, %76 : i64
cf.cond_br %120, ^bb22, ^bb23
^bb22:
%121 = arith.constant 1 : i32
%122 = llvm.load %118 : !llvm.ptr -> i64
%123 = arith.trunci %121 : i32 to i8
%124 = llvm.getelementptr %77[%122] : (!llvm.ptr, i64) -> !llvm.ptr, i8
llvm.store %123, %124 : i8, !llvm.ptr
%125 = llvm.load %118 : !llvm.ptr -> i64
%126 = llvm.load %93 : !llvm.ptr -> i64
%127 = arith.addi %125, %126 : i64
llvm.store %127, %118 : i64, !llvm.ptr
cf.br ^bb21
^bb23:
cf.br ^bb20
^bb19:
cf.br ^bb20
^bb20:
%128 = llvm.load %93 : !llvm.ptr -> i64
%129 = arith.constant 1 : i32
%131 = arith.extsi %129 : i32 to i64
%130 = arith.addi %128, %131 : i64
llvm.store %130, %93 : i64, !llvm.ptr
cf.br ^bb15
^bb17:
%132 = llvm.mlir.addressof @N : !llvm.ptr
%133 = llvm.load %132 : !llvm.ptr -> i64
%134 = llvm.mlir.constant(1 : i64) : i64
%135 = llvm.alloca %134 x i64 : (i64) -> !llvm.ptr
llvm.store %133, %135 : i64, !llvm.ptr
%136 = arith.constant 0 : i32
%137 = llvm.mlir.addressof @pc : !llvm.ptr
%138 = llvm.load %137 : !llvm.ptr -> i64
%139 = arith.index_cast %136 : i32 to index
%140 = arith.index_cast %138 : i32 to index
%142 = arith.constant 1 : index
%143 = arith.constant -1 : index
%144 = arith.cmpi sle, %139, %140 : index
%141 = arith.select %144, %142, %143 : index
cf.br ^bb24(%139 : index)
^bb24(%145: index):
%146 = arith.cmpi slt, %145, %140 : index
%147 = arith.cmpi sgt, %145, %140 : index
%148 = arith.select %144, %146, %147 : i1
cf.cond_br %148, ^bb25(%145 : index), ^bb26(%145 : index)
^bb25(%149: index):
%150 = llvm.load %135 : !llvm.ptr -> i64
%152 = arith.constant 1 : i32
%153 = arith.extsi %152 : i32 to i64
%154 = arith.index_cast %149 : index to i64
%151 = func.call @generate(%153, %154) : (i64, i64) -> i64
%155 = arith.addi %150, %151 : i64
llvm.store %155, %135 : i64, !llvm.ptr
%156 = arith.addi %149, %141 : index
cf.br ^bb24(%156 : index)
^bb26(%157: index):
func.call @free(%77) : (!llvm.ptr) -> ()
%160 = llvm.mlir.addressof @primes : !llvm.ptr
%161 = llvm.load %160 : !llvm.ptr -> !llvm.ptr
func.call @free(%161) : (!llvm.ptr) -> ()
%162 = llvm.mlir.addressof @str_0 : !llvm.ptr
%163 = llvm.load %135 : !llvm.ptr -> i64
%164 = llvm.call @printf(%162, %163) vararg(!llvm.func<i32 (ptr, ...)>) : (!llvm.ptr, i64) -> i32
%165 = arith.constant 0 : i32
func.return %165 : i32
}
}