Problem 099

Line number of maximal base^exp (compare via exp*log(base)).

View problem on Project Euler

Performance comparison

Flow source

# Project Euler 099
# Line number of maximal base^exp (compare via exp*log(base)).

extern {
    function fopen(path: string, mode: string) -> ptr<void>
    function fgetc(f: ptr<void>) -> i32
    function fclose(f: ptr<void>) -> i32
    function log(x: f64) -> f64
}

function read_int(f: ptr<void>) -> i64 {
    let mut c: i32 = fgetc(f)
    while c >= 0 && (c < 48 || c > 57) {
        c = fgetc(f)
    }
    if c < 0 { return 0 - 1 }
    let mut v: i64 = 0
    while c >= 48 && c <= 57 {
        v = v * 10 + ((c - 48) as i64)
        c = fgetc(f)
    }
    return v
}

function main() -> i32 {
    let f: ptr<void> = fopen("data/p099.txt", "r")
    if f == null {
        printf("failed to read data/p099.txt\n")
        return 1
    }
    let mut best: f64 = 0.0 - 1.0
    let mut best_line: i64 = 0
    let mut line: i64 = 1
    while line <= 1000 {
        let base: i64 = read_int(f)
        let exp: i64 = read_int(f)
        if base < 0 { break }
        let score: f64 = (exp as f64) * log(base as f64)
        if score > best {
            best = score
            best_line = line
        }
        line = line + 1
    }
    fclose(f)
    printf("%lld\n", best_line)
    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; }

int64_t read_int_ptr_void(void* f);
int32_t main(void);





int64_t read_int_ptr_void(void* f) {
    int32_t c = fgetc(f);
    while ((c >= 0 && (c < 48 || c > 57))) {
        c = fgetc(f);
    }
    if (c < 0) {
        return (0 - 1);
    }
    int64_t v = 0;
    while ((c >= 48 && c <= 57)) {
        v = ((v * 10) + ((int64_t)((c - 48))));
        c = fgetc(f);
    }
    return v;
}

int32_t main(void) {
    void* f = (void*)(fopen("data/p099.txt", "r"));
    if (f == NULL) {
        printf("failed to read data/p099.txt\n");
        return 1;
    }
    double best = (0.0 - 1.0);
    int64_t best_line = 0;
    int64_t line = 1;
    while (line <= 1000) {
        int64_t base = read_int_ptr_void(f);
        int64_t exp = read_int_ptr_void(f);
        if (base < 0) {
            break;
        }
        double score = (((double)(exp)) * log(((double)(base))));
        if (score > best) {
            best = score;
            best_line = line;
        }
        line = (line + 1);
    }
    fclose(f);
    printf("%lld\n", best_line);
    return 0;
}

Generated MLIR

module {
  llvm.func @printf(!llvm.ptr, ...) -> i32
  llvm.mlir.global internal constant @str_0("data/p099.txt\00") {addr_space = 0 : i32} : !llvm.array<14 x i8>
  llvm.mlir.global internal constant @str_1("r\00") {addr_space = 0 : i32} : !llvm.array<2 x i8>
  llvm.mlir.global internal constant @str_2("failed to read data/p099.txt\n\00") {addr_space = 0 : i32} : !llvm.array<30 x i8>
  llvm.mlir.global internal constant @str_3("%lld\n\00") {addr_space = 0 : i32} : !llvm.array<6 x i8>
  func.func private @fopen(!llvm.ptr, !llvm.ptr) -> !llvm.ptr
  func.func private @fgetc(!llvm.ptr) -> i32
  func.func private @fclose(!llvm.ptr) -> i32
  func.func private @log(f64) -> f64
  func.func @read_int(%arg0: !llvm.ptr) -> i64 {
    %0 = func.call @fgetc(%arg0) : (!llvm.ptr) -> i32
    %1 = llvm.mlir.constant(1 : i64) : i64
    %2 = llvm.alloca %1 x i32 : (i64) -> !llvm.ptr
    llvm.store %0, %2 : i32, !llvm.ptr
    cf.br ^bb0
    ^bb0:
    %3 = llvm.load %2 : !llvm.ptr -> i32
    %4 = arith.constant 0 : i32
    %5 = arith.cmpi sge, %3, %4 : i32
    %6 = scf.if %5 -> (i1) {
      %7 = llvm.load %2 : !llvm.ptr -> i32
      %8 = arith.constant 48 : i32
      %9 = arith.cmpi slt, %7, %8 : i32
      %10 = scf.if %9 -> (i1) {
        %11 = arith.constant true
        scf.yield %11 : i1
      } else {
        %12 = llvm.load %2 : !llvm.ptr -> i32
        %13 = arith.constant 57 : i32
        %14 = arith.cmpi sgt, %12, %13 : i32
        scf.yield %14 : i1
      }
      scf.yield %10 : i1
    } else {
      %15 = arith.constant false
      scf.yield %15 : i1
    }
    cf.cond_br %6, ^bb1, ^bb2
    ^bb1:
      %16 = func.call @fgetc(%arg0) : (!llvm.ptr) -> i32
      llvm.store %16, %2 : i32, !llvm.ptr
      cf.br ^bb0
    ^bb2:
    %17 = llvm.load %2 : !llvm.ptr -> i32
    %18 = arith.constant 0 : i32
    %19 = arith.cmpi slt, %17, %18 : i32
    cf.cond_br %19, ^bb3, ^bb4
    ^bb3:
      %20 = arith.constant 0 : i32
      %21 = arith.constant 1 : i32
      %22 = arith.subi %20, %21 : i32
      %23 = arith.extsi %22 : i32 to i64
      func.return %23 : i64
    ^bb4:
      cf.br ^bb5
    ^bb5:
    %24 = arith.constant 0 : i32
    %25 = arith.extsi %24 : i32 to i64
    %26 = llvm.mlir.constant(1 : i64) : i64
    %27 = llvm.alloca %26 x i64 : (i64) -> !llvm.ptr
    llvm.store %25, %27 : i64, !llvm.ptr
    cf.br ^bb6
    ^bb6:
    %28 = llvm.load %2 : !llvm.ptr -> i32
    %29 = arith.constant 48 : i32
    %30 = arith.cmpi sge, %28, %29 : i32
    %31 = scf.if %30 -> (i1) {
      %32 = llvm.load %2 : !llvm.ptr -> i32
      %33 = arith.constant 57 : i32
      %34 = arith.cmpi sle, %32, %33 : i32
      scf.yield %34 : i1
    } else {
      %35 = arith.constant false
      scf.yield %35 : i1
    }
    cf.cond_br %31, ^bb7, ^bb8
    ^bb7:
      %36 = llvm.load %27 : !llvm.ptr -> i64
      %37 = arith.constant 10 : i32
      %39 = arith.extsi %37 : i32 to i64
      %38 = arith.muli %36, %39 : i64
      %40 = llvm.load %2 : !llvm.ptr -> i32
      %41 = arith.constant 48 : i32
      %42 = arith.subi %40, %41 : i32
      %43 = arith.extsi %42 : i32 to i64
      %44 = arith.addi %38, %43 : i64
      llvm.store %44, %27 : i64, !llvm.ptr
      %45 = func.call @fgetc(%arg0) : (!llvm.ptr) -> i32
      llvm.store %45, %2 : i32, !llvm.ptr
      cf.br ^bb6
    ^bb8:
    %46 = llvm.load %27 : !llvm.ptr -> i64
    func.return %46 : i64
  }
  func.func @main() -> i32 {
    %48 = llvm.mlir.addressof @str_0 : !llvm.ptr
    %49 = llvm.mlir.addressof @str_1 : !llvm.ptr
    %47 = func.call @fopen(%48, %49) : (!llvm.ptr, !llvm.ptr) -> !llvm.ptr
    %50 = llvm.mlir.zero : !llvm.ptr
    %51 = llvm.icmp "eq" %47, %50 : !llvm.ptr
    cf.cond_br %51, ^bb9, ^bb10
    ^bb9:
      %52 = llvm.mlir.addressof @str_2 : !llvm.ptr
      %53 = llvm.call @printf(%52) vararg(!llvm.func<i32 (ptr, ...)>) : (!llvm.ptr) -> i32
      %54 = arith.constant 1 : i32
      func.return %54 : i32
    ^bb10:
      cf.br ^bb11
    ^bb11:
    %55 = arith.constant 0.0 : f32
    %56 = arith.constant 1.0 : f32
    %57 = arith.subf %55, %56 : f32
    %58 = arith.extf %57 : f32 to f64
    %59 = llvm.mlir.constant(1 : i64) : i64
    %60 = llvm.alloca %59 x f64 : (i64) -> !llvm.ptr
    llvm.store %58, %60 : f64, !llvm.ptr
    %61 = arith.constant 0 : i32
    %62 = arith.extsi %61 : i32 to i64
    %63 = llvm.mlir.constant(1 : i64) : i64
    %64 = llvm.alloca %63 x i64 : (i64) -> !llvm.ptr
    llvm.store %62, %64 : i64, !llvm.ptr
    %65 = arith.constant 1 : i32
    %66 = arith.extsi %65 : i32 to i64
    %67 = llvm.mlir.constant(1 : i64) : i64
    %68 = llvm.alloca %67 x i64 : (i64) -> !llvm.ptr
    llvm.store %66, %68 : i64, !llvm.ptr
    cf.br ^bb12
    ^bb12:
    %69 = llvm.load %68 : !llvm.ptr -> i64
    %70 = arith.constant 1000 : i32
    %72 = arith.extsi %70 : i32 to i64
    %71 = arith.cmpi sle, %69, %72 : i64
    cf.cond_br %71, ^bb13, ^bb14
    ^bb13:
      %73 = func.call @read_int(%47) : (!llvm.ptr) -> i64
      %74 = func.call @read_int(%47) : (!llvm.ptr) -> i64
      %75 = arith.constant 0 : i32
      %77 = arith.extsi %75 : i32 to i64
      %76 = arith.cmpi slt, %73, %77 : i64
      cf.cond_br %76, ^bb15, ^bb16
      ^bb15:
        cf.br ^bb14
      ^bb16:
        cf.br ^bb17
      ^bb17:
      %78 = arith.sitofp %74 : i64 to f64
      %79 = arith.sitofp %73 : i64 to f64
      %80 = math.log %79 : f64
      %81 = arith.mulf %78, %80 : f64
      %82 = llvm.load %60 : !llvm.ptr -> f64
      %83 = arith.cmpf ogt, %81, %82 : f64
      cf.cond_br %83, ^bb18, ^bb19
      ^bb18:
        llvm.store %81, %60 : f64, !llvm.ptr
        %84 = llvm.load %68 : !llvm.ptr -> i64
        llvm.store %84, %64 : i64, !llvm.ptr
        cf.br ^bb20
      ^bb19:
        cf.br ^bb20
      ^bb20:
      %85 = llvm.load %68 : !llvm.ptr -> i64
      %86 = arith.constant 1 : i32
      %88 = arith.extsi %86 : i32 to i64
      %87 = arith.addi %85, %88 : i64
      llvm.store %87, %68 : i64, !llvm.ptr
      cf.br ^bb12
    ^bb14:
    %89 = func.call @fclose(%47) : (!llvm.ptr) -> i32
    %90 = llvm.mlir.addressof @str_3 : !llvm.ptr
    %91 = llvm.load %64 : !llvm.ptr -> i64
    %92 = llvm.call @printf(%90, %91) vararg(!llvm.func<i32 (ptr, ...)>) : (!llvm.ptr, i64) -> i32
    %93 = arith.constant 0 : i32
    func.return %93 : i32
  }
}