Changeset 08ed947 for tests/zombies/string-perf/make-corpus.cfa

Timestamp:

Feb 23, 2022, 6:13:02 PM (3 years ago)

Author:

Michael Brooks <mlbrooks@…>

Branches:

ADT, ast-experimental, enum, master, pthread-emulation, qualifiedEnum

Children:

afe9e45, c5af4f9

Parents:

cc7bbe6

Message:

Roll up of string changes for performance testing/improvement, and a couple API features supporting them.

String API changes:
Defining a tuning knob to control the heap growth policy (relapaces former 10% hardcode, downgraded to a default)
Implementing findFrom (allowing find-non-first); leaving find as find-first.

String implementation perf improvements:
Calling C-malloc directly instead of via CFA-alloc.
Replacings loops that copy with memmove calls.
Replacings loops that search for a value with memchr calls.

String perf testing realized:
Makefile supporting several prog-*.cfa, chosen by OPERATION value (implies prog.cfa changes to support the adjusted protocol)
Adjusting the starter/accumulater declarations in PEQ and PTA to behave consistently in cfa v cpp.
Adding tests: allocation, find, normalize, pass-by-val, pass-by-x.
Adding helper shell scripts for: generating flame graphs, collecting/crunching allocation stats using Mubeen's malloc wrappers

File:

• tests/zombies/string-perf/make-corpus.cfa (modified) (3 diffs)

tests/zombies/string-perf/make-corpus.cfa

@@ -3 +3 @@
 #include <limits.h>
 #include <unistd.h>
+#include <string.h>
+
+// U(0,1)
+static double U() {
+    return (double)rand() / (double)INT_MAX;
+}
 
 // generate random draws from a geometric distribution of the given mean
@@ -14 +20 @@
 static int nextGeoRand() {
     // ret = ⌊ln(U)/ln(1−p)⌋ where U ~ U(0, 1)
-    double U = (double)rand() / (double)INT_MAX;
-    return 1 + (int) (log(U) / denom);
+    return 1 + (int) (log(U()) / denom);
 }
 
-// write a randomly generated alphabetic string whose length is drawn from above distribution
-static void emit1() {
-    int lim = nextGeoRand();
+// write a randomly generated alphabetic string whose length is adjused from a draw of the above distribution
+static void emit1( int offset, double mcfreq, char mchar ) {
+    int lim = offset + nextGeoRand();
     // printf("==%d\n", lim);
     for (i; lim) {
-        char emit = 'a' + (rand() % ('z'-'a'));
+        char emit;
+        if (U() < mcfreq) emit = mchar;
+        else emit = 'a' + (rand() % ('z'-'a'));
         printf("%c", emit);
     }
@@ -29 +36 @@
 }
 
-// usage: ./make-corpus toGen mean
+// usage: ./make-corpus toGen mean [offset=0] [mcfreq=0.0] [mchar='-']
+//
+// Outputs alphabetic (plus magic-char) strings, one per line.
+// toGen: number of strings (lines)
+// 
+// generated length ~  offset + geo(mean)
+//                  >= 1
+//
+// offset=0,  mean=1:  constant length 1
+// offset=0,  mean=2:  lengths go like number of coin tosses it takes to get heads
+// offset=0,  mean=6:  lengths go like number of cube die rolls it takes to get :::
+// offset=15, mean=1:  constant length 16
+// offset=15, mean=2:  population's minimum is 16 and mean is 17
+//
+// Magic Char (mc) does not affect these lengths.  Any mc occurrence replaces an alphabetic char.
+// mcfreq: (in [0,1]) expected fraction of the characters output that are mchar
+//
 int main(int argc, char ** argv) {
-    assert(argc == 3);
 
-    int toGen = atoi(argv[1]);
-    assert(toGen > 0);
-    assert(toGen < 1000000);
+    int toGen;
+    int mean;
+    int offset = 0;
+    double mcfreq = 0.0;
+    char mchar = '-';
 
-    int mean = atoi(argv[2]);
-    assert(mean > 0);
-    assert(mean < 1000);
+    assert(argc >= 3 && argc <= 6);
+    switch(argc) {
+        case 6:
+            assert(strlen(argv[5]) == 0);
+            mchar = argv[5][0];
+        case 5:
+            mcfreq = atof(argv[4]);
+            assert(mcfreq >= 0.0 && mcfreq <= 1.0);
+        case 4:
+            offset = atoi(argv[3]);
+            assert(offset >= 0 && offset < 10000);
+        default:
+            mean = atoi(argv[2]);
+            assert(mean > 0);
+            assert(mean < 1000);
+            toGen = atoi(argv[1]);
+            assert(toGen > 0);
+            assert(toGen < 1000000);
+    }
 
     initialize(mean);
     for( i; toGen ) {
-        emit1();
+        emit1(offset, mcfreq, mchar);
     }
 }