diff --git a/Makefile b/Makefile
index 912af0d..deb0aa9 100644
--- a/Makefile
+++ b/Makefile
@@ -20,13 +20,17 @@ SRC_CXX = $(wildcard src/*.cpp)
 
 INCLUDE=include
 
+# Set compile-time features
+#  * PARALLEL - Enable multithreaded processing
+FEATURES?=PARALLEL
+
 META_FLAGS:=-D_PROJECT_AUTHOR="\"$(AUTHOR)\"" -D_PROJECT_DESCRIPTION="\"$(DESCRIPTION)\"" -D_PROJECT_NAME="\"$(PROJECT)\"" \
 		-D_PROJECT_LICENSE="\"$(LICENSE)\"" \
 		-D_VERSION_MAJOR=$(VERSION_MAJ) -D_VERSION_MINOR=$(VERSION_MIN) \
 		-D_VERSION_BUGFIX=$(VERSION_BF) -D_VERSION_REVISION=$(VERSION_REV) \
 		-D_PROJECT_COMPILED=$(COMP_TIME)
 
-COMMON_FLAGS+= -W -Wall -fno-strict-aliasing $(addprefix -I,$(INCLUDE)) $(META_FLAGS)
+COMMON_FLAGS+= -W -Wall -fno-strict-aliasing $(addprefix -I,$(INCLUDE)) $(META_FLAGS) $(addprefix -D_FEATURE_,$(FEATURES))
 
 ARCH?=native
 OPT_FLAGS+= -fgraphite -fopenmp -floop-parallelize-all -ftree-parallelize-loops=4 \
diff --git a/include/comp.h b/include/comp.h
index ab52503..ff3ea60 100644
--- a/include/comp.h
+++ b/include/comp.h
@@ -4,6 +4,20 @@
 #include <macros.h>
 #include <ints.h>
 
+typedef struct comp_aggregate {
+	bool all_matched;
+
+	int idx_first_failure;
+
+	usize num_results;
+	struct comp_single_result {
+		map_t* _shared mapping;
+
+		bool matched;
+		usize slice_start;
+	} aggr[];
+} comp_multires_t;
+
 /// Find `needle` in `haystack`, sets the start of `needle`'s `origin` in `haystack`'s to `pos` and returns `true` if a match is found, otherwise returns false.
 bool cmp_find(const map_t *pIN needle, const map_t *pIN haystack, usize *pOUT pos);
 /// Check `needle` against `nhaystacks` number of haystack maps, store the offset in `sizes[n]` where `n` is the haystack number.
@@ -12,6 +26,9 @@ bool cmp_find(const map_t *pIN needle, const map_t *pIN haystack, usize *pOUT po
 ///
 /// # Panics
 /// Will `FATAL` if any of the haystack pointers are `NULL`
-int cmp_find_many(usize nhaystacks; const map_t *pIN needle, usize sizes[pOUT nhaystacks], usize nhaystacks, ...);
+int cmp_find_many(const map_t *pIN needle, usize nhaystacks, usize sizes[pOUT nhaystacks], ...);
+
+// The return value of this function must be `free()`d after use
+comp_multires_t* comp_match_all(map_t *pIN needle, usize nh, map_t hs[pIN nh], bool abort_on_fail);
 
 #endif /* _COMP_H */
diff --git a/src/comp.c b/src/comp.c
index 74f3185..c2b65d2 100644
--- a/src/comp.c
+++ b/src/comp.c
@@ -1,5 +1,6 @@
 #define _GNU_SOURCE
 
+#include <stdlib.h>
 #include <stdarg.h>
 #include <string.h>
 
@@ -7,6 +8,8 @@
 #include <ints.h>
 #include <map.h>
 
+#include <comp.h>
+
 
 bool cmp_find(const map_t *pIN needle, const map_t *pIN haystack, usize *pOUT pos)
 {
@@ -14,15 +17,15 @@ bool cmp_find(const map_t *pIN needle, const map_t *pIN haystack, usize *pOUT po
 	u8* substr = memmem(start = haystack->origin, haystack->len,
 			needle->origin, needle->len);
 	if(!substr) return false;
-	debug_assert(substr > start);
+	debug_assert(substr >= start);
 	*pos = (usize) (substr - start);
 	return true;
 }
 
-int cmp_find_many(usize nhaystacks; const map_t *pIN needle, usize sizes[pOUT nhaystacks], usize nhaystacks, ...)
+int cmp_find_many(const map_t *pIN needle, usize nhaystacks, usize sizes[pOUT nhaystacks], ...)
 {
 	va_list v_haystacks;
-	va_start(v_haystacks, nhaystacks);
+	va_start(v_haystacks, sizes);
 
 	const map_t* pINOUT haystack;
 	register int rval=-1;
@@ -40,3 +43,46 @@ int cmp_find_many(usize nhaystacks; const map_t *pIN needle, usize sizes[pOUT nh
 	va_end(v_haystacks);	
 	return rval;
 }
+
+comp_multires_t* comp_match_all(map_t *pIN needle, usize nh, map_t hs[pIN nh], bool abort_on_fail)
+{
+	comp_multires_t* result = malloc(sizeof(comp_multires_t) + (sizeof(struct comp_single_result) * nh));
+	debug_assert(result);
+
+	result->all_matched = true;
+	result->idx_first_failure = -1;
+	result->num_results = nh;
+
+
+	usize i;
+	for(i =0;i<nh;i++)
+	{
+		usize start=0;
+		bool matched = cmp_find(needle, hs+i, &start);
+		struct comp_single_result res = {
+			.mapping = hs+i,
+			.matched = matched,
+			.slice_start = start,
+		};
+		TRACE("Result for %lu (%p): Matched: %s, slice start: %lu", i, hs+i, matched ? "yes" : "no", start);
+		result->aggr[i] = res;
+		if(!res.matched) {
+			WARN("Matching haystack %lu failed", i);
+			result->all_matched = false;
+			if(result->idx_first_failure < 0) {
+				INFO("First match failure is %lu", i);
+				result->idx_first_failure = (int)i;
+			}
+			if(abort_on_fail) {
+				result->num_results = i;
+				break;
+			}
+		}
+	}
+	INFO("Aggregate result for %lu / %lu haystack matches: Full passed: %s, first filaure: %d", 
+							i, nh,
+							result->all_matched ? "yes" : "no", 
+							result->idx_first_failure);
+	TRACE("Output result aggregate size: %lu (alloc: %p)", sizeof(comp_multires_t) + (sizeof(struct comp_single_result) * nh), result);
+	return result;
+}
diff --git a/src/main.c b/src/main.c
index c3d23c4..804ad8a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -88,18 +88,28 @@ inv_args:
 	// Remove exe name from argv: now is (needle, haystacks...)
 	argv+=1;
 	// Setup haystack maps
-	map_t haystacks[argc-2];
-	TRACE("Attempting to map %d haystacks", argc-2);
+	usize hsn = AS(argc-2, usize);
+	map_t haystacks[hsn];
+	TRACE("Attempting to map %lu haystacks", hsn);
 	if(!map_haystacks((const char**)(argv+1), haystacks)) return PROG_RET_MAP_HAYSTACK_FAILED;
-	
+
+#ifdef _FEATURE_PARALLEL // Multi-threaded	
 	//TODO: Setup thread-pool.
 	//TODO: Dispatch haystack maps to threadpool.
 	//TODO: Use either `cmp_find()` or `cmp_find_many()` to find the `needle` (mapped above) within those haystacks.
 	//TODO: Within the threadpool: output information regarding each match/nonmatch.
 	//TODO: Join the threadpool and consolidate results.
 	//TODO: Iterate through the haystack numbers match results, return the first non-match haystack number through `PROG_RET_MATCH_HAYSTACK_N_FAILED(n)` (haystack numbers are always nonzero). If all were matched, return 0
+#else // Single-threaded
+	INFO("Computing result for %lu haystacks...", hsn);
+	comp_multires_t* full_result = comp_match_all(&needle, hsn, haystacks, false);
+	// Number of results actually computed by `comp_match_all()` may differ from `hsn` if `abort_on_fail` is true (currently its hardcoded to false but that may change.)
+	usize cres = full_result->num_results;
+	INFO("Computed result: Suc. Matched %lu / %lu hs. Full match: %s (first failure: %d)", cres, hsn, full_result->all_matched ? "yes" : "no", full_result->idx_first_failure);
+	free(full_result);
+#endif
 
-	for(int i=0;i<(argc-2);i++) {
+	for(int i=0;i<(int)hsn;i++) {
 		INFO("Unmapping haystack haystack file `%s' (#%d) (map addr %p)", argv[i+1], i+1, haystacks+i);
 		if(!map_handle_err(map_free(haystacks[i]))) return PROG_RET_UNMAP_HAYSTACK_N_FAILED(i+1);
 	}
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