diff --git a/testdata/abs_sqrt.txt b/testdata/abs_sqrt.txt
index fa05a04..d6368e2 100644
--- a/testdata/abs_sqrt.txt
+++ b/testdata/abs_sqrt.txt
@@ -4,9 +4,15 @@
 # float32. The inputs include -0, infinities, NaNs, and negative numbers, and the
 # output is compared bit for bit.
 
+# testmain/output was recorded on amd64: a NaN that an operation creates (the square
+# root of a negative number, 0 times infinity) has the sign bit set there and clear
+# on arm64, so the recording is compared only on amd64, and on every target the
+# simd build is compared with the scalar build of the same machine.
+
 # The scalar program is the reference behavior.
 exec go run ./testmain
-cmp stdout testmain/output
+[GOARCH:amd64] cmp stdout testmain/output
+cp stdout scalar.out
 
 cp ops.go ops.go.orig
 loopvec -split .
@@ -18,7 +24,8 @@ cmp ops.go ops.go.guarded
 # The simd build must behave identically.
 env GOEXPERIMENT=simd
 exec go run ./testmain
-cmp stdout testmain/output
+[GOARCH:amd64] cmp stdout testmain/output
+cmp stdout scalar.out
 
 -- go.mod --
 module example.com/test
diff --git a/testdata/activation_temp.txt b/testdata/activation_temp.txt
index dc2f51b..5526f8d 100644
--- a/testdata/activation_temp.txt
+++ b/testdata/activation_temp.txt
@@ -4,8 +4,14 @@
 # if/else if, then use it. Results must match the scalar loop bit for bit, NaN,
 # infinities and signed zeros included.
 
+# testmain/output was recorded on amd64: a NaN that an operation creates (the square
+# root of a negative number, 0 times infinity) has the sign bit set there and clear
+# on arm64, so the recording is compared only on amd64, and on every target the
+# simd build is compared with the scalar build of the same machine.
+
 exec go run ./testmain
-cmp stdout testmain/output
+[GOARCH:amd64] cmp stdout testmain/output
+cp stdout scalar.out
 
 cp ops.go ops.go.orig
 loopvec -split .
@@ -16,7 +22,8 @@ cmp ops.go ops.go.guarded
 
 env GOEXPERIMENT=simd
 exec go run ./testmain
-cmp stdout testmain/output
+[GOARCH:amd64] cmp stdout testmain/output
+cmp stdout scalar.out
 
 -- go.mod --
 module example.com/test
diff --git a/testdata/invariant_call.txt b/testdata/invariant_call.txt
index 903e7ab..3f1fcf5 100644
--- a/testdata/invariant_call.txt
+++ b/testdata/invariant_call.txt
@@ -3,8 +3,14 @@
 # the call is evaluated once before the loop. The results must match the scalar loop
 # bit for bit, which is the only way to compare NaN and negative zero.
 
+# testmain/output was recorded on amd64: a NaN that an operation creates (the square
+# root of a negative number, 0 times infinity) has the sign bit set there and clear
+# on arm64, so the recording is compared only on amd64, and on every target the
+# simd build is compared with the scalar build of the same machine.
+
 exec go run ./testmain
-cmp stdout testmain/output
+[GOARCH:amd64] cmp stdout testmain/output
+cp stdout scalar.out
 
 cp ops.go ops.go.orig
 loopvec -split .
@@ -15,7 +21,8 @@ cmp ops.go ops.go.guarded
 
 env GOEXPERIMENT=simd
 exec go run ./testmain
-cmp stdout testmain/output
+[GOARCH:amd64] cmp stdout testmain/output
+cmp stdout scalar.out
 
 -- go.mod --
 module example.com/test