diff --git a/Makefile b/Makefile
index 8fb319baf..77c7bcbee 100644
--- a/Makefile
+++ b/Makefile
@@ -62,7 +62,7 @@ TESTEXECUTABLES=jsoncheck numberparsingcheck stringparsingcheck pointercheck
 COMPARISONEXECUTABLES=minifiercompetition parsingcompetition parseandstatcompetition distinctuseridcompetition allparserscheckfile allparsingcompetition
 SUPPLEMENTARYEXECUTABLES=parse_noutf8validation parse_nonumberparsing parse_nostringparsing
 
-HEADERS= include/simdjson/simdutf8check_haswell.h include/simdjson/simdutf8check_westmere.h include/simdjson/simdutf8check_arm64.h include/simdjson/stringparsing.h include/simdjson/stringparsing_arm64.h  include/simdjson/stringparsing_haswell.h include/simdjson/stringparsing_westmere.h include/simdjson/numberparsing.h include/simdjson/jsonparser.h include/simdjson/common_defs.h include/simdjson/jsonioutil.h benchmark/benchmark.h benchmark/linux/linux-perf-events.h include/simdjson/parsedjson.h include/simdjson/stage1_find_marks.h  include/simdjson/stage1_find_marks_arm64.h  include/simdjson/stage1_find_marks_haswell.h   include/simdjson/stage1_find_marks_westmere.h include/simdjson/stage2_build_tape.h include/simdjson/jsoncharutils.h include/simdjson/jsonformatutils.h include/simdjson/stage1_find_marks_flatten.h include/simdjson/stage1_find_marks_flatten_haswell.h
+HEADERS= include/simdjson/simdutf8check_haswell.h include/simdjson/simdutf8check_westmere.h include/simdjson/simdutf8check_arm64.h include/simdjson/stringparsing.h include/simdjson/stringparsing_arm64.h  include/simdjson/stringparsing_haswell.h include/simdjson/stringparsing_westmere.h include/simdjson/numberparsing.h include/simdjson/jsonparser.h include/simdjson/common_defs.h include/simdjson/jsonioutil.h benchmark/benchmark.h benchmark/linux/linux-perf-events.h include/simdjson/parsedjson.h include/simdjson/stage1_find_marks.h  include/simdjson/stage1_find_marks_arm64.h  include/simdjson/stage1_find_marks_haswell.h   include/simdjson/stage1_find_marks_westmere.h include/simdjson/stage2_build_tape.h include/simdjson/jsoncharutils.h include/simdjson/jsonformatutils.h include/simdjson/stage1_find_marks_flatten_common.h include/simdjson/stage1_find_marks_flatten_haswell.h
 LIBFILES=src/jsonioutil.cpp src/jsonparser.cpp src/simdjson.cpp src/stage1_find_marks.cpp src/stage2_build_tape.cpp src/parsedjson.cpp src/parsedjsoniterator.cpp
 MINIFIERHEADERS=include/simdjson/jsonminifier.h include/simdjson/simdprune_tables.h
 MINIFIERLIBFILES=src/jsonminifier.cpp
diff --git a/amalgamation.sh b/amalgamation.sh
index 7c4e53e68..3ae789103 100755
--- a/amalgamation.sh
+++ b/amalgamation.sh
@@ -17,6 +17,7 @@ $SCRIPTPATH/src/simdjson.cpp
 $SCRIPTPATH/src/jsonioutil.cpp
 $SCRIPTPATH/src/jsonminifier.cpp
 $SCRIPTPATH/src/jsonparser.cpp
+$SCRIPTPATH/include/simdjson/stage1_find_marks_flatten_haswell.h
 $SCRIPTPATH/src/stage1_find_marks.cpp
 $SCRIPTPATH/src/stage2_build_tape.cpp
 $SCRIPTPATH/src/parsedjson.cpp
@@ -41,8 +42,6 @@ $SCRIPTPATH/include/simdjson/simdutf8check_arm64.h
 $SCRIPTPATH/include/simdjson/jsonminifier.h
 $SCRIPTPATH/include/simdjson/parsedjson.h
 $SCRIPTPATH/include/simdjson/stage1_find_marks.h
-$SCRIPTPATH/include/simdjson/stage1_find_marks_flatten.h
-$SCRIPTPATH/include/simdjson/stage1_find_marks_flatten_haswell.h
 $SCRIPTPATH/include/simdjson/stage1_find_marks_westmere.h
 $SCRIPTPATH/include/simdjson/stage1_find_marks_haswell.h
 $SCRIPTPATH/include/simdjson/stage1_find_marks_arm64.h
diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index 1783999c1..f7dd742b7 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -20,7 +20,7 @@ set(SIMDJSON_INCLUDE
     ${SIMDJSON_INCLUDE_DIR}/stage1_find_marks.h
     ${SIMDJSON_INCLUDE_DIR}/stage1_find_marks_arm64.h
     ${SIMDJSON_INCLUDE_DIR}/stage1_find_marks_common.h
-    ${SIMDJSON_INCLUDE_DIR}/stage1_find_marks_flatten.h
+    ${SIMDJSON_INCLUDE_DIR}/stage1_find_marks_flatten_common.h
     ${SIMDJSON_INCLUDE_DIR}/stage1_find_marks_flatten_haswell.h
     ${SIMDJSON_INCLUDE_DIR}/stage1_find_marks_haswell.h
     ${SIMDJSON_INCLUDE_DIR}/stage1_find_marks_westmere.h
diff --git a/include/simdjson/stage1_find_marks.h b/include/simdjson/stage1_find_marks.h
index bcf8e8991..24a0bd154 100644
--- a/include/simdjson/stage1_find_marks.h
+++ b/include/simdjson/stage1_find_marks.h
@@ -116,6 +116,15 @@ int find_structural_bits(const char *buf, size_t len,
   return find_structural_bits((const uint8_t *)buf, len, pj);
 }
 
+// flatten out values in 'bits' assuming that they are are to have values of idx
+// plus their position in the bitvector, and store these indexes at
+// base_ptr[base] incrementing base as we go
+// will potentially store extra values beyond end of valid bits, so base_ptr
+// needs to be large enough to handle this
+template <Architecture T = Architecture::NATIVE>
+really_inline void flatten_bits(uint32_t *base_ptr, uint32_t &base,
+                                uint32_t idx, uint64_t bits);
+
 } // namespace simdjson
 
 #endif
diff --git a/include/simdjson/stage1_find_marks_arm64.h b/include/simdjson/stage1_find_marks_arm64.h
index 1dd550aec..51a778794 100644
--- a/include/simdjson/stage1_find_marks_arm64.h
+++ b/include/simdjson/stage1_find_marks_arm64.h
@@ -3,7 +3,6 @@
 
 #include "simdjson/simdutf8check_arm64.h"
 #include "simdjson/stage1_find_marks.h"
-#include "simdjson/stage1_find_marks_flatten.h"
 
 #ifdef IS_ARM64
 namespace simdjson {
diff --git a/include/simdjson/stage1_find_marks_common.h b/include/simdjson/stage1_find_marks_common.h
index 73c05af3c..26ef6ad1e 100644
--- a/include/simdjson/stage1_find_marks_common.h
+++ b/include/simdjson/stage1_find_marks_common.h
@@ -92,7 +92,7 @@ really_inline uint64_t find_quote_mask_and_bits<TARGETED_ARCHITECTURE>(
 }
 
 // Find structural bits in a 64-byte chunk.
-void find_structural_bits_64(
+really_inline void find_structural_bits_64(
     const uint8_t *buf, size_t idx, uint32_t *base_ptr, uint32_t &base,
     uint64_t &prev_iter_ends_odd_backslash, uint64_t &prev_iter_inside_quote,
     uint64_t &prev_iter_ends_pseudo_pred, uint64_t &structurals,
@@ -113,12 +113,7 @@ void find_structural_bits_64(
   /* take the previous iterations structural bits, not our current
    * iteration,
    * and flatten */
-#ifdef IS_X86_64
-  if (TARGETED_ARCHITECTURE == Architecture::HASWELL)
-    simdjson::haswell::flatten_bits(base_ptr, base, idx, structurals);
-  else
-#endif
-    simdjson::flatten_bits(base_ptr, base, idx, structurals);
+  flatten_bits<TARGETED_ARCHITECTURE>(base_ptr, base, idx, structurals);
 
   uint64_t whitespace;
   find_whitespace_and_structurals<TARGETED_ARCHITECTURE>(in, whitespace,
@@ -200,12 +195,7 @@ int find_structural_bits<TARGETED_ARCHITECTURE>(const uint8_t *buf, size_t len,
 
   /* finally, flatten out the remaining structurals from the last iteration
    */
-#ifdef IS_X86_64
-  if (TARGETED_ARCHITECTURE == Architecture::HASWELL)
-    simdjson::haswell::flatten_bits(base_ptr, base, idx, structurals);
-  else
-#endif
-    simdjson::flatten_bits(base_ptr, base, idx, structurals);
+  flatten_bits<TARGETED_ARCHITECTURE>(base_ptr, base, idx, structurals);
 
   pj.n_structural_indexes = base;
   /* a valid JSON file cannot have zero structural indexes - we should have
diff --git a/include/simdjson/stage1_find_marks_flatten.h b/include/simdjson/stage1_find_marks_flatten_common.h
similarity index 74%
rename from include/simdjson/stage1_find_marks_flatten.h
rename to include/simdjson/stage1_find_marks_flatten_common.h
index 3958adca3..74cdc961c 100644
--- a/include/simdjson/stage1_find_marks_flatten.h
+++ b/include/simdjson/stage1_find_marks_flatten_common.h
@@ -1,6 +1,12 @@
-#ifndef SIMDJSON_STAGE1_FIND_MARKS_FLATTEN_H
-#define SIMDJSON_STAGE1_FIND_MARKS_FLATTEN_H
+// This file contains a non-architecture-specific version of "flatten" used in stage1.
+// It is intended to be included multiple times and compiled multiple times
+// We assume the file in which it is include already includes
+// "simdjson/stage1_find_marks.h" (this simplifies amalgation)
 
+#ifdef TARGETED_ARCHITECTURE
+#ifdef TARGETED_REGION
+
+TARGETED_REGION
 namespace simdjson {
 
 #ifdef SIMDJSON_NAIVE_FLATTEN // useful for benchmarking
@@ -8,8 +14,9 @@ namespace simdjson {
 // This is just a naive implementation. It should be normally
 // disable, but can be used for research purposes to compare
 // again our optimized version.
-really_inline void flatten_bits(uint32_t *base_ptr, uint32_t &base,
-                                uint32_t idx, uint64_t bits) {
+template <>
+really_inline void flatten_bits<TARGETED_ARCHITECTURE>(uint32_t *base_ptr, uint32_t &base,
+                                                       uint32_t idx, uint64_t bits) {
   uint32_t *out_ptr = base_ptr + base;
   idx -= 64;
   while (bits != 0) {
@@ -26,8 +33,9 @@ really_inline void flatten_bits(uint32_t *base_ptr, uint32_t &base,
 // base_ptr[base] incrementing base as we go
 // will potentially store extra values beyond end of valid bits, so base_ptr
 // needs to be large enough to handle this
-really_inline void flatten_bits(uint32_t *base_ptr, uint32_t &base,
-                                uint32_t idx, uint64_t bits) {
+template<>
+really_inline void flatten_bits<TARGETED_ARCHITECTURE>(uint32_t *base_ptr, uint32_t &base,
+                                                       uint32_t idx, uint64_t bits) {
   // In some instances, the next branch is expensive because it is mispredicted.
   // Unfortunately, in other cases,
   // it helps tremendously.
@@ -88,6 +96,13 @@ really_inline void flatten_bits(uint32_t *base_ptr, uint32_t &base,
   base = next_base;
 }
 #endif // SIMDJSON_NAIVE_FLATTEN
-} // namespace simdjson
 
-#endif // SIMDJSON_STAGE1_FIND_MARKS_FLATTEN_H
+} // namespace simdjson
+UNTARGET_REGION
+
+#else
+#error TARGETED_REGION must be specified before including.
+#endif // TARGETED_REGION
+#else
+#error TARGETED_ARCHITECTURE must be specified before including.
+#endif // TARGETED_ARCHITECTURE
diff --git a/include/simdjson/stage1_find_marks_flatten_haswell.h b/include/simdjson/stage1_find_marks_flatten_haswell.h
index ac48e9005..02dbfa5bd 100644
--- a/include/simdjson/stage1_find_marks_flatten_haswell.h
+++ b/include/simdjson/stage1_find_marks_flatten_haswell.h
@@ -1,8 +1,5 @@
-#ifndef SIMDJSON_STAGE1_FIND_MARKS_FLATTEN_HASWELL_H
-#define SIMDJSON_STAGE1_FIND_MARKS_FLATTEN_HASWELL_H
-
 // This file provides the same function as
-// stage1_find_marks_flatten.h, but uses Intel intrinsics.
+// stage1_find_marks_flatten_common.h, but uses Intel intrinsics.
 // This should provide better performance on Visual Studio
 // and other compilers that do a conservative optimization.
 
@@ -20,15 +17,15 @@
 
 TARGET_HASWELL
 namespace simdjson {
-namespace haswell {
 
 // flatten out values in 'bits' assuming that they are are to have values of idx
 // plus their position in the bitvector, and store these indexes at
 // base_ptr[base] incrementing base as we go
 // will potentially store extra values beyond end of valid bits, so base_ptr
 // needs to be large enough to handle this
-really_inline void flatten_bits(uint32_t *base_ptr, uint32_t &base,
-                                uint32_t idx, uint64_t bits) {
+template<>
+really_inline void flatten_bits<Architecture::HASWELL>(uint32_t *base_ptr, uint32_t &base,
+													   uint32_t idx, uint64_t bits) {
   // In some instances, the next branch is expensive because it is mispredicted.
   // Unfortunately, in other cases,
   // it helps tremendously.
@@ -88,8 +85,6 @@ really_inline void flatten_bits(uint32_t *base_ptr, uint32_t &base,
   }
   base = next_base;
 }
-} // namespace haswell
 } // namespace simdjson
 UNTARGET_REGION
 #endif // IS_X86_64
-#endif // SIMDJSON_STAGE1_FIND_MARKS_FLATTEN_H
diff --git a/include/simdjson/stage1_find_marks_haswell.h b/include/simdjson/stage1_find_marks_haswell.h
index 017c52829..d6ff7113c 100644
--- a/include/simdjson/stage1_find_marks_haswell.h
+++ b/include/simdjson/stage1_find_marks_haswell.h
@@ -3,7 +3,6 @@
 
 #include "simdjson/simdutf8check_haswell.h"
 #include "simdjson/stage1_find_marks.h"
-#include "simdjson/stage1_find_marks_flatten_haswell.h"
 
 #ifdef IS_X86_64
 
diff --git a/include/simdjson/stage1_find_marks_westmere.h b/include/simdjson/stage1_find_marks_westmere.h
index a25e07259..f39b8a969 100644
--- a/include/simdjson/stage1_find_marks_westmere.h
+++ b/include/simdjson/stage1_find_marks_westmere.h
@@ -3,7 +3,6 @@
 
 #include "simdjson/simdutf8check_westmere.h"
 #include "simdjson/stage1_find_marks.h"
-#include "simdjson/stage1_find_marks_flatten.h"
 
 #ifdef IS_X86_64
 
diff --git a/src/stage1_find_marks.cpp b/src/stage1_find_marks.cpp
index 563d764bc..9075682ad 100644
--- a/src/stage1_find_marks.cpp
+++ b/src/stage1_find_marks.cpp
@@ -3,17 +3,18 @@
 
 #ifdef IS_X86_64
 
-#include "simdjson/stage1_find_marks_haswell.h"
-#include "simdjson/stage1_find_marks_westmere.h"
-
 #define TARGETED_ARCHITECTURE Architecture::HASWELL
 #define TARGETED_REGION TARGET_HASWELL
+#include "simdjson/stage1_find_marks_flatten_haswell.h"
+#include "simdjson/stage1_find_marks_haswell.h"
 #include "simdjson/stage1_find_marks_common.h"
 #undef TARGETED_ARCHITECTURE
 #undef TARGETED_REGION
 
 #define TARGETED_ARCHITECTURE Architecture::WESTMERE
 #define TARGETED_REGION TARGET_WESTMERE
+#include "simdjson/stage1_find_marks_flatten_common.h"
+#include "simdjson/stage1_find_marks_westmere.h"
 #include "simdjson/stage1_find_marks_common.h"
 #undef TARGETED_ARCHITECTURE
 #undef TARGETED_REGION
@@ -22,10 +23,10 @@
 
 #ifdef IS_ARM64
 
-#include "simdjson/stage1_find_marks_arm64.h"
-
 #define TARGETED_ARCHITECTURE Architecture::ARM64
 #define TARGETED_REGION TARGET_ARM64
+#include "simdjson/stage1_find_marks_flatten_common.h"
+#include "simdjson/stage1_find_marks_arm64.h"
 #include "simdjson/stage1_find_marks_common.h"
 #undef TARGETED_ARCHITECTURE
 #undef TARGETED_REGION