ZSTD_maxCLevel now limited to 21 for 32-bit binaries.

CI tests for constrained memory runs with max level on 32-bit binaries.

tests/fuzzer.c

@@ -1982,7 +1982,7 @@ static int basicUnitTests(U32 const seed, double compressibility)
             int const rowLevelEnd = 8;
 
             DISPLAYLEVEL(3, "test%3i : flat-dictionary efficiency test : \n", testNb++);
-            assert(maxLevel == 22);
+            assert(maxLevel == (MEM_32bits() ? 21 : 22));
             RDG_genBuffer(CNBuffer, flatdictSize + contentSize, compressibility, 0., seed);
             DISPLAYLEVEL(4, "content hash : %016llx;  dict hash : %016llx \n", XXH64(contentStart, contentSize, 0), XXH64(dict, flatdictSize, 0));
 

tests/playTests.sh

@@ -1538,6 +1538,11 @@ elif [ "$longCSize19wlog23" -gt "$optCSize19wlog23" ]; then
     exit 1
 fi
 
+if [ -n "$CHECK_CONSTRAINED_MEM" ]; then
+    println "\n===>  zsdt constrained memory tests "
+    # shellcheck disable=SC2039
+    (ulimit -Sv 500000 ; datagen -g2M | zstd -22 --single-thread --ultra > /dev/null)
+fi
 
 if [ "$1" != "--test-large-data" ]; then
     println "Skipping large data tests"