From 10193b37e384cd1c99a6fbc50f8cb8597517cc3a Mon Sep 17 00:00:00 2001
From: Valerio Setti <valerio.setti@nordicsemi.no>
Date: Wed, 28 Jan 2026 00:00:33 +0100
Subject: [PATCH] tests: scripts: add new component to test alignment with GCC
 O3 optizations

This is meant to test a bug found on:
- Little endian platforms other than x86 or ARM (these have specific
  optimizations available);
- GCC versions from 10 to 14.2 (below and above are fine);
- Optimization level "-O3" (lower levels are fine).

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
---
 tests/scripts/components-compiler.sh | 44 ++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/tests/scripts/components-compiler.sh b/tests/scripts/components-compiler.sh
index 1eac64f54d..ed89d818ca 100644
--- a/tests/scripts/components-compiler.sh
+++ b/tests/scripts/components-compiler.sh
@@ -172,3 +172,47 @@ component_test_zeroize () {
         done
     done
 }
+
+# This originated from an issue (https://github.com/Mbed-TLS/TF-PSA-Crypto/issues/665) found
+# in GCM when the library is built with GCC "10.0 <= version <= 14.2" on platforms other than
+# x86 and ARM64.
+component_test_tf_psa_crypto_optimized_alignment() {
+    msg "build: verify alignment with O3 optimizations in GCC"
+
+    # Disable optimizations for x86 (and ARM64) so that alignment related problems in
+    # "alignment.h" can be tested also on standard PC.
+    scripts/config.py unset MBEDTLS_AESNI_C
+    scripts/config.py unset MBEDTLS_AESCE_C
+
+    # "-O3" is the optimization level that causes issues: the compiler tries to
+    # optimize operations order and if memory dependencies are not respected
+    # (as it happens in issue tf-psa-crypto#665) this completely messes up results.
+    EXTRA_C_FLAGS="-O3"
+    # Forcedly ignore "MBEDTLS_EFFICIENT_UNALIGNED_ACCESS" on x86 so that we
+    # can test the problematic case, i.e. the case where uint64 integers are
+    # accessed through "mbedtls_uint64_unaligned_t" structs.
+    EXTRA_C_FLAGS="$EXTRA_C_FLAGS -DMBEDTLS_ALIGNMENT_DISABLE_EFFICENT_UNALIGNED_ACCESS"
+    # Adding '-g3' flag doesn't affect testing, BUT it allows to dump the generated
+    # assembly code for "gcm.o" module for inspection. To do this use the
+    # following command:
+    # > objdump -S --disassemble out_of_source_build/drivers/builtin/CMakeFiles/builtin.dir/src/gcm.c.o > gcm.s
+    # A file named "gcm.s" will be generated containing a mix of C and corresponding
+    # assembly code.
+    EXTRA_C_FLAGS="$EXTRA_C_FLAGS -g3"
+
+    cd $OUT_OF_SOURCE_DIR
+    cmake -DCMAKE_C_COMPILER=gcc -DCMAKE_C_FLAGS=" $EXTRA_C_FLAGS " "$TF_PSA_CRYPTO_ROOT_DIR"
+    make
+
+    msg "test: verify alignment with O3 optimizations in GCC"
+    make test
+}
+
+support_test_tf_psa_crypto_optimized_alignment() {
+    case $(gcc -dumpfullversion 2>/dev/null) in
+        ""|?.*) false;; # too old
+        10.*|11.*|12.*|13.*) true;;
+        14.[012].*) true;;
+        *) false;; # too recent
+    esac
+}