Fixed issue with aliasing local variables

ISPC++ now produces valid code, or an appropriate error message, for all
of my test cases.

func.cpp

@@ -635,7 +635,7 @@ Function::GenerateIR() {
 const bool
 Function::IsPolyFunction() const {
     for (size_t i = 0; i < args.size(); i++) {
-        if (args[i] && args[i]->type->IsPolymorphicType()) {
+        if (args[i]->type->IsPolymorphicType()) {
             return true;
         }
     }

module.cpp

@@ -1061,6 +1061,8 @@ Module::AddFunctionDeclaration(const std::string &name,
 
                 const Type *ret = eft->GetReturnType();
                 if (Type::EqualForReplacement(ret, pt)) {
+                    printf("Replaced return type %s\n",
+                           ret->GetString().c_str());
                     ret = PolyType::ReplaceType(ret, *te);
                 }
 
@@ -1996,13 +1998,11 @@ lPrintPolyFunctionWrappers(FILE *file, const std::vector<std::string> &funcs) {
         for (size_t j=0; j<poly.size(); j++) {
             const FunctionType *ftype = CastType<FunctionType>(poly[j]->type);
             Assert(ftype);
-            if (ftype->isExported || ftype->isExternC) {
-                std::string decl = ftype->GetCDeclaration(funcs[i]);
-                fprintf(file, "    %s {\n", decl.c_str());
+            std::string decl = ftype->GetCDeclaration(funcs[i]);
+            fprintf(file, "    %s {\n", decl.c_str());
 
-                std::string call = ftype->GetCCall(poly[j]->name);
-                fprintf(file, "        return %s;\n    }\n", call.c_str());
-            }
+            std::string call = ftype->GetCCall(poly[j]->name);
+            fprintf(file, "        return %s;\n    }\n", call.c_str());
         }
     }
 

parse.yy

@@ -37,7 +37,7 @@
 /* one for 'if', one for 'cif' */
 %expect 2
 
-%define parse.error verbose
+%error-verbose
 
 %code requires {
 

tests_ispcpp/CycleTimer.h

@@ -1,177 +0,0 @@
-#ifndef _SYRAH_CYCLE_TIMER_H_
-#define _SYRAH_CYCLE_TIMER_H_
-
-#if defined(__APPLE__)
-  #if defined(__x86_64__)
-    #include <sys/sysctl.h>
-  #else
-    #include <mach/mach.h>
-    #include <mach/mach_time.h>
-  #endif // __x86_64__ or not
-
-  #include <stdio.h>  // fprintf
-  #include <stdlib.h> // exit
-
-#elif _WIN32
-#  include <windows.h>
-#  include <time.h>
-#else
-#  include <stdio.h>
-#  include <stdlib.h>
-#  include <string.h>
-#  include <sys/time.h>
-#endif
-
-
-  // This uses the cycle counter of the processor.  Different
-  // processors in the system will have different values for this.  If
-  // you process moves across processors, then the delta time you
-  // measure will likely be incorrect.  This is mostly for fine
-  // grained measurements where the process is likely to be on the
-  // same processor.  For more global things you should use the
-  // Time interface.
-
-  // Also note that if you processors' speeds change (i.e. processors
-  // scaling) or if you are in a heterogenous environment, you will
-  // likely get spurious results.
-  class CycleTimer {
-  public:
-    typedef unsigned long long SysClock;
-
-    //////////
-    // Return the current CPU time, in terms of clock ticks.
-    // Time zero is at some arbitrary point in the past.
-    static SysClock currentTicks() {
-#if defined(__APPLE__) && !defined(__x86_64__)
-      return mach_absolute_time();
-#elif defined(_WIN32)
-      LARGE_INTEGER qwTime;
-      QueryPerformanceCounter(&qwTime);
-      return qwTime.QuadPart;
-#elif defined(__x86_64__)
-      unsigned int a, d;
-      asm volatile("rdtsc" : "=a" (a), "=d" (d));
-      return static_cast<unsigned long long>(a) |
-        (static_cast<unsigned long long>(d) << 32);
-#elif defined(__ARM_NEON__) && 0 // mrc requires superuser.
-      unsigned int val;
-      asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r"(val));
-      return val;
-#else
-      timespec spec;
-      clock_gettime(CLOCK_THREAD_CPUTIME_ID, &spec);
-      return CycleTimer::SysClock(static_cast<float>(spec.tv_sec) * 1e9 + static_cast<float>(spec.tv_nsec));
-#endif
-    }
-
-    //////////
-    // Return the current CPU time, in terms of seconds.
-    // This is slower than currentTicks().  Time zero is at
-    // some arbitrary point in the past.
-    static double currentSeconds() {
-      return currentTicks() * secondsPerTick();
-    }
-
-    //////////
-    // Return the conversion from seconds to ticks.
-    static double ticksPerSecond() {
-      return 1.0/secondsPerTick();
-    }
-
-    static const char* tickUnits() {
-#if defined(__APPLE__) && !defined(__x86_64__)
-      return "ns";
-#elif defined(__WIN32__) || defined(__x86_64__)
-      return "cycles";
-#else
-      return "ns"; // clock_gettime
-#endif
-    }
-
-    //////////
-    // Return the conversion from ticks to seconds.
-    static double secondsPerTick() {
-      static bool initialized = false;
-      static double secondsPerTick_val;
-      if (initialized) return secondsPerTick_val;
-#if defined(__APPLE__)
-  #ifdef __x86_64__
-      int args[] = {CTL_HW, HW_CPU_FREQ};
-      unsigned int Hz;
-      size_t len = sizeof(Hz);
-      if (sysctl(args, 2, &Hz, &len, NULL, 0) != 0) {
-         fprintf(stderr, "Failed to initialize secondsPerTick_val!\n");
-         exit(-1);
-      }
-      secondsPerTick_val = 1.0 / (double) Hz;
-  #else
-      mach_timebase_info_data_t time_info;
-      mach_timebase_info(&time_info);
-
-      // Scales to nanoseconds without 1e-9f
-      secondsPerTick_val = (1e-9*static_cast<double>(time_info.numer))/
-        static_cast<double>(time_info.denom);
-  #endif // x86_64 or not
-#elif defined(_WIN32)
-      LARGE_INTEGER qwTicksPerSec;
-      QueryPerformanceFrequency(&qwTicksPerSec);
-      secondsPerTick_val = 1.0/static_cast<double>(qwTicksPerSec.QuadPart);
-#else
-      FILE *fp = fopen("/proc/cpuinfo","r");
-      char input[1024];
-      if (!fp) {
-         fprintf(stderr, "CycleTimer::resetScale failed: couldn't find /proc/cpuinfo.");
-         exit(-1);
-      }
-      // In case we don't find it, e.g. on the N900
-      secondsPerTick_val = 1e-9;
-      while (!feof(fp) && fgets(input, 1024, fp)) {
-        // NOTE(boulos): Because reading cpuinfo depends on dynamic
-        // frequency scaling it's better to read the @ sign first
-        float GHz, MHz;
-        if (strstr(input, "model name")) {
-          char* at_sign = strstr(input, "@");
-          if (at_sign) {
-            char* after_at = at_sign + 1;
-            char* GHz_str = strstr(after_at, "GHz");
-            char* MHz_str = strstr(after_at, "MHz");
-            if (GHz_str) {
-              *GHz_str = '\0';
-              if (1 == sscanf(after_at, "%f", &GHz)) {
-                //printf("GHz = %f\n", GHz);
-                secondsPerTick_val = 1e-9f / GHz;
-                break;
-              }
-            } else if (MHz_str) {
-              *MHz_str = '\0';
-              if (1 == sscanf(after_at, "%f", &MHz)) {
-                //printf("MHz = %f\n", MHz);
-                secondsPerTick_val = 1e-6f / GHz;
-                break;
-              }
-            }
-          }
-        } else if (1 == sscanf(input, "cpu MHz : %f", &MHz)) {
-          //printf("MHz = %f\n", MHz);
-          secondsPerTick_val = 1e-6f / MHz;
-          break;
-        }
-      }
-      fclose(fp);
-#endif
-
-      initialized = true;
-      return secondsPerTick_val;
-    }
-
-    //////////
-    // Return the conversion from ticks to milliseconds.
-    static double msPerTick() {
-      return secondsPerTick() * 1000.0;
-    }
-
-  private:
-    CycleTimer();
-  };
-
-#endif // #ifndef _SYRAH_CYCLE_TIMER_H_

tests_ispcpp/Makefile

@@ -1,15 +1,12 @@
 CXX=g++
-CXXFLAGS=-std=c++11 -O3 -lm -lpthread
+CXXFLAGS=-std=c++11 -O2
 
 ISPC=../ispc
-ISPCFLAGS=--target=avx2 -O3 --arch=x86-64
+ISPCFLAGS=--target=sse4-x2 -O2 --arch=x86-64
 
-%.out : %.cpp %.o tasksys.o
+%.out : %.cpp %.o
 	$(CXX) $(CXXFLAGS) -o $@ $^
 
-tasksys.o : ../examples/tasksys.cpp
-	$(CXX) $(CXXFLAGS) -c -o $@ $^
-
 $ : $.o
 
 %.o : %.ispc

tests_ispcpp/array.ispc

@@ -1,13 +0,0 @@
-export void array(uniform int N, uniform integer * uniform X) {
-    integer *A = new integer[N/2];
-
-    foreach (i = 0 ... N/2) {
-        A[i] = X[i] + X[N/2 + i];
-    }
-
-    foreach (i = 0 ... N) {
-        X[i] = A[i/2];
-    }
-
-    delete[] A;
-}

tests_ispcpp/error_5.ispc

@@ -1,17 +0,0 @@
-//@error
-
-floating$0 mult(floating$0 x, floating$1 y) {
-    return x * y;
-}
-
-export void saxpy(uniform int N,
-                  uniform floating$0 scale,
-                  uniform floating$1 X[],
-                  uniform floating$1 Y[],
-                  uniform floating$2 result[])
-{
-    foreach (i = 0 ... N) {
-        floating$ tmp = mult(scale, X[i]) + Y[i];
-        result[i] = tmp;
-    }
-}

tests_ispcpp/error_6.ispc

@@ -1,14 +0,0 @@
-number pow(number b, int a) {
-    number out = b;
-    for (int i = 1; i<a; i++) {
-        out *= b;
-    }
-
-    return out;
-}
-
-export void square(uniform int N, uniform number$-1 b[], uniform number$-1 out[]) {
-    foreach (i = 0 ... N) {
-        out[i] = pow(b[i], 2);
-    }
-}

tests_ispcpp/error_7.ispc

@@ -1,13 +0,0 @@
-floating foo(floating a, floating b) {
-    floating d = a / b;
-    if (d < 0.)
-        return 0.;
-
-    return d;
-}
-
-export void bar(uniform integer * uniform X, uniform int N) {
-    foreach (i = 0 ... N-1) {
-        X[i] = foo(X[i], X[i+1]);
-    }
-}

tests_ispcpp/function.ispc

@@ -1,15 +1,15 @@
 floating saxpy_helper(floating scale,
-                      floating$3 x,
-                      floating$3 y) {
+                      floating<0> x,
+                      floating<0> y) {
     return scale * x + y;
 }
 
 
 export void saxpy(uniform int N,
-                  uniform floating$0 scale,
-                  uniform floating$1 X[],
-                  uniform floating$1 Y[],
-                  uniform floating$2 result[])
+                  uniform floating<0> scale,
+                  uniform floating<1> X[],
+                  uniform floating<1> Y[],
+                  uniform floating<2> result[])
 {
     foreach (i = 0 ... N) {
         result[i] = saxpy_helper(scale, X[i], Y[i]);

tests_ispcpp/sqrt.cpp

@@ -1,212 +0,0 @@
-#include <stdio.h>
-#include <algorithm>
-#include <pthread.h>
-#include <math.h>
-#include <cmath>
-
-#include "CycleTimer.h"
-#include "sqrt.h"
-
-using namespace ispc;
-
-void sqrtSerial(int N,
-                float initialGuess,
-                float values[],
-                float output[])
-{
-
-    static const float kThreshold = 0.00001f;
-
-    for (int i=0; i<N; i++) {
-
-        float x = values[i];
-        float guess = initialGuess;
-
-        float error = fabs(guess * guess * x - 1.f);
-
-        while (error > kThreshold) {
-            guess = (3.f * guess - x * guess * guess * guess) * 0.5f;
-            error = fabs(guess * guess * x - 1.f);
-        }
-
-        output[i] = x * guess;
-    }
-}
-
-void sqrtSerial(int N,
-                double initialGuess,
-                double values[],
-                double output[])
-{
-
-    static const double kThreshold = 0.00001f;
-
-    for (int i=0; i<N; i++) {
-
-        double x = values[i];
-        double guess = initialGuess;
-
-        double error = std::abs(guess * guess * x - 1.);
-
-        while (error > kThreshold) {
-            guess = (3. * guess - x * guess * guess * guess) * 0.5;
-            error = std::abs(guess * guess * x - 1.);
-        }
-
-        output[i] = x * guess;
-    }
-}
-
-static void verifyResult(int N, float* result, float* gold) {
-    for (int i=0; i<N; i++) {
-        if (fabs(result[i] - gold[i]) > 1e-4) {
-            printf("Error: [%d] Got %f expected %f\n", i, result[i], gold[i]);
-        }
-    }
-}
-
-static void verifyResult(int N, double* result, double* gold) {
-    for (int i=0; i<N; i++) {
-        if (std::abs(result[i] - gold[i]) > 1e-4) {
-            printf("Error: [%d] Got %f expected %f\n", i, result[i], gold[i]);
-        }
-    }
-}
-
-int main() {
-
-    const unsigned int N = 20 * 1000 * 1000;
-    const float initialGuess = 1.0f;
-    const double dinitialGuess = 1.0;
-
-    float* values = new float[N];
-    float* output = new float[N];
-    float* gold = new float[N];
-
-    double* dvalues = new double[N];
-    double* doutput = new double[N];
-    double* dgold = new double[N];
-
-    for (unsigned int i=0; i<N; i++)
-    {
-        // random input values
-        values[i] = .001f + 2.998f * static_cast<float>(rand()) / RAND_MAX;
-        dvalues[i] = .001 + 2.998 * static_cast<double>(rand()) / RAND_MAX;
-        output[i] = 0.f;
-        doutput[i] = 0.;
-    }
-
-    // generate a gold version to check results
-    for (unsigned int i=0; i<N; i++) {
-        gold[i] = sqrt(values[i]);
-        dgold[i] = sqrt(dvalues[i]);
-    }
-
-    //
-    // And run the serial implementation 3 times, again reporting the
-    // minimum time.
-    //
-    double minSerial = 1e30;
-    for (int i = 0; i < 5; ++i) {
-        double startTime = CycleTimer::currentSeconds();
-        sqrtSerial(N, initialGuess, values, output);
-        double endTime = CycleTimer::currentSeconds();
-        minSerial = std::min(minSerial, endTime - startTime);
-    }
-
-    printf("[sqrt float serial]:\t\t[%.3f] ms\n", minSerial * 1000);
-    verifyResult(N, output, gold);
-
-    double minDSerial = 1e30;
-    for (int i = 0; i < 5; ++i) {
-        double startTime = CycleTimer::currentSeconds();
-        sqrtSerial(N, dinitialGuess, dvalues, doutput);
-        double endTime = CycleTimer::currentSeconds();
-        minDSerial = std::min(minDSerial, endTime - startTime);
-    }
-
-    printf("[sqrt double serial]:\t\t[%.3f] ms\n", minDSerial * 1000);
-    verifyResult(N, doutput, dgold);
-
-    // Clear out the buffer
-    for (unsigned int i = 0; i < N; ++i) {
-        output[i] = 0;
-        doutput[i] = 0;
-    }
-
-
-    //
-    // Compute the image using the ispc implementation; report the minimum
-    // time of three runs.
-    //
-    double minISPC = 1e30;
-    for (int i = 0; i < 5; ++i) {
-        double startTime = CycleTimer::currentSeconds();
-        ispc::sqrt_ispc(N, initialGuess, values, output);
-        double endTime = CycleTimer::currentSeconds();
-        minISPC = std::min(minISPC, endTime - startTime);
-    }
-
-    printf("[sqrt float ispc]:\t\t[%.3f] ms\n", minISPC * 1000);
-
-    verifyResult(N, output, gold);
-
-    double minDISPC = 1e30;
-    for (int i = 0; i < 5; ++i) {
-        double startTime = CycleTimer::currentSeconds();
-        ispc::sqrt_ispc(N, dinitialGuess, dvalues, doutput);
-        double endTime = CycleTimer::currentSeconds();
-        minDISPC = std::min(minDISPC, endTime - startTime);
-    }
-
-    printf("[sqrt double ispc]:\t\t[%.3f] ms\n", minDISPC * 1000);
-
-    verifyResult(N, doutput, dgold);
-
-    // Clear out the buffer
-    for (unsigned int i = 0; i < N; ++i) {
-        output[i] = 0;
-        doutput[i] = 0;
-    }
-
-    //
-    // Tasking version of the ISPC code
-    //
-    double minTaskISPC = 1e30;
-    for (int i = 0; i < 3; ++i) {
-        double startTime = CycleTimer::currentSeconds();
-        ispc::sqrt_ispc_withtasks(N, initialGuess, values, output);
-        double endTime = CycleTimer::currentSeconds();
-        minTaskISPC = std::min(minTaskISPC, endTime - startTime);
-    }
-
-    printf("[sqrt float task ispc]:\t\t[%.3f] ms\n", minTaskISPC * 1000);
-
-    verifyResult(N, output, gold);
-
-    double minDTaskISPC = 1e30;
-    for (int i = 0; i < 3; ++i) {
-        double startTime = CycleTimer::currentSeconds();
-        ispc::sqrt_ispc_withtasks(N, dinitialGuess, dvalues, doutput);
-        double endTime = CycleTimer::currentSeconds();
-        minDTaskISPC = std::min(minDTaskISPC, endTime - startTime);
-    }
-
-    printf("[sqrt double task ispc]:\t[%.3f] ms\n", minDTaskISPC * 1000);
-
-    verifyResult(N, output, gold);
-
-    printf("\t\t\t\t(%.2fx speedup from ISPC float)\n", minSerial/minISPC);
-    printf("\t\t\t\t(%.2fx speedup from ISPC double)\n", minDSerial/minDISPC);
-    printf("\t\t\t\t(%.2fx speedup from task ISPC float)\n", minSerial/minTaskISPC);
-    printf("\t\t\t\t(%.2fx speedup from task ISPC double)\n", minDSerial/minDTaskISPC);
-
-    delete[] values;
-    delete[] output;
-    delete[] gold;
-    delete[] dvalues;
-    delete[] doutput;
-    delete[] dgold;
-
-    return 0;
-}

tests_ispcpp/sqrt.ispc

@@ -1,62 +0,0 @@
-
-static const float kThreshold = 0.00001f;
-
-export void sqrt_ispc(uniform int N,
-                      uniform floating initialGuess,
-                      uniform floating values[],
-                      uniform floating output[])
-{
-    foreach (i = 0 ... N) {
-
-        floating x = values[i];
-        floating guess = initialGuess;
-
-        floating pred = abs(guess * guess * x - 1.f);
-
-        while (pred > kThreshold) {
-            guess = (3.f * guess - x * guess * guess * guess) * 0.5f;
-            pred = abs(guess * guess * x - 1.f);
-        }
-
-        output[i] = x * guess;
-
-    }
-}
-
-task void sqrt_ispc_task(uniform int N,
-                         uniform int span,
-                         uniform floating initialGuess,
-                         uniform floating values[],
-                         uniform floating output[])
-{
-
-    uniform int indexStart = taskIndex * span;
-    uniform int indexEnd = min(N, indexStart + span);
-
-    foreach (i = indexStart ... indexEnd) {
-
-        floating x = values[i];
-        floating guess = initialGuess;
-
-        floating pred = abs(guess * guess * x - 1.f);
-
-        while (pred > kThreshold) {
-            guess = (3.f * guess - x * guess * guess * guess) * 0.5f;
-            pred = abs(guess * guess * x - 1.f);
-        }
-
-        output[i] = x * guess;
-
-    }
-}
-
-export void sqrt_ispc_withtasks(uniform int N,
-                                uniform floating initialGuess,
-                                uniform floating values[],
-                                uniform floating output[])
-{
-
-    uniform int span = N / 64;  // 64 tasks
-
-    launch[N/span] sqrt_ispc_task(N, span, initialGuess, values, output);
-}

tests_ispcpp/varying.cpp

@@ -6,7 +6,7 @@
 int main() {
     float A[256];
     double B[256];
-    float outA[256];
+    double outA[256];
     double outB[256];
 
 
@@ -15,7 +15,7 @@ int main() {
         B[i] = 1. / (i+1);
     }
 
-    ispc::square(256, (float*)&A, (float*)&outA);
+    ispc::square(256, (float*)&A, (double*)&outA);
 
     ispc::square(256, (double*)&B, (double*)&outB);
 

tests_ispcpp/varying.ispc

@@ -1,5 +1,5 @@
-number pow(number b, int a) {
-    number out = b;
+floating foo(const uniform int a, floating b) {
+    floating out = b;
     for (int i = 1; i<a; i++) {
         out *= b;
     }
@@ -7,8 +7,8 @@ number pow(number b, int a) {
     return out;
 }
 
-export void square(uniform int N, uniform number b[], uniform number out[]) {
+export void square(uniform int N, uniform floating b[], uniform double out[]) {
     foreach (i = 0 ... N) {
-        out[i] = pow(b[i], 2);
+        out[i] = foo(2, b[i]);
     }
 }