Andrew kindly catched the bug (in my program, not in GCC, of course) so I'm
sending the hopefully final patch here.
diff -Nru highway-1.2.0/debian/changelog highway-1.2.0/debian/changelog
--- highway-1.2.0/debian/changelog 2024-06-10 17:52:26.000000000 +0200
+++ highway-1.2.0/debian/changelog 2024-07-16 13:00:51.000000000 +0200
@@ -1,3 +1,9 @@
+highway (1.2.0-7) oracular; urgency=medium
+
+ * d/tests: Add basic autopkgtest to compile and execute a simple program.
+
+ -- Nathan Pratta Teodosio <nathan.teodo...@canonical.com> Tue, 16 Jul 2024 13:00:51 +0200
+
highway (1.2.0-2) unstable; urgency=medium
* d/patches: Import upstream fix to fix failing test
diff -Nru highway-1.2.0/debian/tests/compile-and-execute highway-1.2.0/debian/tests/compile-and-execute
--- highway-1.2.0/debian/tests/compile-and-execute 1970-01-01 01:00:00.000000000 +0100
+++ highway-1.2.0/debian/tests/compile-and-execute 2024-07-16 13:00:51.000000000 +0200
@@ -0,0 +1,63 @@
+#!/bin/sh
+set -ex
+trap 'rm o' 0
+cflags=$(pkg-config --cflags --libs libhwy)
+c++ -x c++ - -o o -fsanitize=address -Wall -Wextra -Wpedantic $cflags <<EOF
+#include <hwy/highway.h>
+#include <cstring>
+#include <stdio.h>
+#include <time.h>
+#include <stdlib.h>
+
+namespace hn = hwy::HWY_NAMESPACE;
+using T = int;
+void MulAddLoop(const T* HWY_RESTRICT mul_array,
+ const T* HWY_RESTRICT add_array,
+ const size_t size, T* HWY_RESTRICT x_array) {
+ const hn::ScalableTag<T> d;
+ for (size_t i = 0; i < size; i += hn::Lanes(d)) {
+ const auto mul = hn::Load(d, mul_array + i);
+ const auto add = hn::Load(d, add_array + i);
+ auto x = hn::Load(d, x_array + i);
+ x = hn::MulAdd(mul, x, add);
+ hn::Store(x, d, x_array + i);
+ }
+}
+int main(){
+ /* Initialize arrays with random small integers. */
+ srand(time(NULL));
+ const hn::ScalableTag<T> d;
+ size_t size = hn::Lanes(d)*3;
+ T *a = (T*)malloc(size*sizeof(T));
+ T *b = (T*)malloc(size*sizeof(T));
+ T *c = (T*)malloc(size*sizeof(T));
+ T *c_orig = (T*)malloc(size*sizeof(T));
+ for(size_t i=0; i<size; i++) {
+ a[i] = rand()%9-4;
+ b[i] = rand()%9-4;
+ c[i] = rand()%9-4;
+ }
+ memcpy(c_orig, c, size*sizeof(T));
+
+ /* Run MulAdd on them. */
+ MulAddLoop(a, b, size, c);
+
+ /* Check that the SIMD function gives the same result as the
+ * unserialized math. */
+ int ret = 0;
+ for(size_t i=0; i<size; i++) {
+ auto expected = c_orig[i]*a[i]+b[i];
+ printf("%zuth element is %d (%d expected); (a,b,c_orig)=(%d,%d,%d).\n",
+ i, c[i], expected, a[i], b[i], c_orig[i]);
+ ret += expected != c[i];
+ }
+
+ free(c_orig);
+ free(c);
+ free(b);
+ free(a);
+ printf("Got %d unexpected results.\n", ret);
+ return ret;
+}
+EOF
+./o
diff -Nru highway-1.2.0/debian/tests/control highway-1.2.0/debian/tests/control
--- highway-1.2.0/debian/tests/control 1970-01-01 01:00:00.000000000 +0100
+++ highway-1.2.0/debian/tests/control 2024-07-16 13:00:51.000000000 +0200
@@ -0,0 +1,3 @@
+Tests: compile-and-execute
+Depends: libhwy-dev, g++, pkgconf
+Restrictions: allow-stderr
