diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 7838d99feec..db69e6983d0 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -1035,7 +1035,10 @@ static const struct tune_params generic_tunings =
   2,	/* min_div_recip_mul_df.  */
   0,	/* max_case_values.  */
   tune_params::AUTOPREFETCHER_WEAK,	/* autoprefetcher_model.  */
-  (AARCH64_EXTRA_TUNE_NONE),	/* tune_flags.  */
+  /* Enabling AARCH64_EXTRA_TUNE_CSE_SVE_VL_CONSTANTS significantly benefits
+     Neoverse V1.  It does not have a noticeable effect on A64FX and should
+     have at most a very minor effect on SVE2 cores.  */
+  (AARCH64_EXTRA_TUNE_CSE_SVE_VL_CONSTANTS),	/* tune_flags.  */
   &generic_prefetch_tune
 };
 
@@ -14485,6 +14488,19 @@ aarch64_parse_override_string (const char* input_string,
   free (string_root);
 }
 
+/* Adjust CURRENT_TUNE (a generic tuning struct) with settings that
+   are best for a generic target with the currently-enabled architecture
+   extensions.  */
+static void
+aarch64_adjust_generic_arch_tuning (struct tune_params &current_tune)
+{
+  /* Neoverse V1 is the only core that is known to benefit from
+     AARCH64_EXTRA_TUNE_CSE_SVE_VL_CONSTANTS.  There is therefore no
+     point enabling it for SVE2 and above.  */
+  if (TARGET_SVE2)
+    current_tune.extra_tuning_flags
+      &= ~AARCH64_EXTRA_TUNE_CSE_SVE_VL_CONSTANTS;
+}
 
 static void
 aarch64_override_options_after_change_1 (struct gcc_options *opts)
@@ -14555,6 +14571,8 @@ aarch64_override_options_internal (struct gcc_options *opts)
      we may later overwrite.  */
   aarch64_tune_params = *(selected_tune->tune);
   aarch64_architecture_version = selected_arch->architecture_version;
+  if (selected_tune->tune == &generic_tunings)
+    aarch64_adjust_generic_arch_tuning (aarch64_tune_params);
 
   if (opts->x_aarch64_override_tune_string)
     aarch64_parse_override_string (opts->x_aarch64_override_tune_string,
diff --git a/gcc/testsuite/g++.target/aarch64/sve/aarch64-sve.exp b/gcc/testsuite/g++.target/aarch64/sve/aarch64-sve.exp
index 4bbe2f50a32..d4761f2d807 100644
--- a/gcc/testsuite/g++.target/aarch64/sve/aarch64-sve.exp
+++ b/gcc/testsuite/g++.target/aarch64/sve/aarch64-sve.exp
@@ -38,6 +38,10 @@ if { [check_effective_target_aarch64_sve] } {
     set sve_flags "-march=armv8.2-a+sve"
 }
 
+# Turn off any codegen tweaks by default that may affect expected assembly.
+# Tests relying on those should turn them on explicitly.
+set sve_flags "$sve_flags -moverride=tune=none"
+
 # Main loop.
 dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.C]] $sve_flags ""
 
diff --git a/gcc/testsuite/g++.target/aarch64/sve/acle/aarch64-sve-acle-asm.exp b/gcc/testsuite/g++.target/aarch64/sve/acle/aarch64-sve-acle-asm.exp
index 0734268313c..84ae95e2ccc 100644
--- a/gcc/testsuite/g++.target/aarch64/sve/acle/aarch64-sve-acle-asm.exp
+++ b/gcc/testsuite/g++.target/aarch64/sve/acle/aarch64-sve-acle-asm.exp
@@ -37,6 +37,10 @@ if { [check_effective_target_aarch64_sve] } {
     set sve_flags "-march=armv8.2-a+sve"
 }
 
+# Turn off any codegen tweaks by default that may affect expected assembly.
+# Tests relying on those should turn them on explicitly.
+set sve_flags "$sve_flags -moverride=tune=none"
+
 global gcc_runtest_parallelize_limit_minor
 if { [info exists gcc_runtest_parallelize_limit_minor] } {
     set old_limit_minor $gcc_runtest_parallelize_limit_minor
diff --git a/gcc/testsuite/g++.target/aarch64/sve/acle/aarch64-sve-acle.exp b/gcc/testsuite/g++.target/aarch64/sve/acle/aarch64-sve-acle.exp
index cb9de753e7a..8d3d8b4a8b3 100644
--- a/gcc/testsuite/g++.target/aarch64/sve/acle/aarch64-sve-acle.exp
+++ b/gcc/testsuite/g++.target/aarch64/sve/acle/aarch64-sve-acle.exp
@@ -44,6 +44,10 @@ if { [check_effective_target_aarch64_sve] } {
     set sve_flags "-march=armv8.2-a+sve"
 }
 
+# Turn off any codegen tweaks by default that may affect expected assembly.
+# Tests relying on those should turn them on explicitly.
+set sve_flags "$sve_flags -moverride=tune=none"
+
 # Main loop.
 set gcc_subdir [string replace $subdir 0 2 gcc]
 set files [glob -nocomplain \
diff --git a/gcc/testsuite/gcc.target/aarch64/sve/aarch64-sve.exp b/gcc/testsuite/gcc.target/aarch64/sve/aarch64-sve.exp
index 622fc92b528..1d3f56690e6 100644
--- a/gcc/testsuite/gcc.target/aarch64/sve/aarch64-sve.exp
+++ b/gcc/testsuite/gcc.target/aarch64/sve/aarch64-sve.exp
@@ -44,6 +44,10 @@ if { [check_effective_target_aarch64_sve] } {
     set sve_flags "-march=armv8.2-a+sve"
 }
 
+# Turn off any codegen tweaks by default that may affect expected assembly.
+# Tests relying on those should turn them on explicitly.
+set sve_flags "$sve_flags -moverride=tune=none"
+
 # Most of the code-quality tests are written for LP64.  Just do the
 # correctness tests for ILP32.
 if { [check_effective_target_ilp32] } {
diff --git a/gcc/testsuite/gcc.target/aarch64/sve/acle/aarch64-sve-acle-asm.exp b/gcc/testsuite/gcc.target/aarch64/sve/acle/aarch64-sve-acle-asm.exp
index 6146e659503..fcd07aaa040 100644
--- a/gcc/testsuite/gcc.target/aarch64/sve/acle/aarch64-sve-acle-asm.exp
+++ b/gcc/testsuite/gcc.target/aarch64/sve/acle/aarch64-sve-acle-asm.exp
@@ -37,6 +37,10 @@ if { [check_effective_target_aarch64_sve] } {
     set sve_flags "-march=armv8.2-a+sve"
 }
 
+# Turn off any codegen tweaks by default that may affect expected assembly.
+# Tests relying on those should turn them on explicitly.
+set sve_flags "$sve_flags -moverride=tune=none"
+
 global gcc_runtest_parallelize_limit_minor
 if { [info exists gcc_runtest_parallelize_limit_minor] } {
     set old_limit_minor $gcc_runtest_parallelize_limit_minor
diff --git a/gcc/testsuite/gcc.target/aarch64/sve/acle/aarch64-sve-acle.exp b/gcc/testsuite/gcc.target/aarch64/sve/acle/aarch64-sve-acle.exp
index a33b65a2a74..2f36f1c57d1 100644
--- a/gcc/testsuite/gcc.target/aarch64/sve/acle/aarch64-sve-acle.exp
+++ b/gcc/testsuite/gcc.target/aarch64/sve/acle/aarch64-sve-acle.exp
@@ -44,6 +44,10 @@ if { [check_effective_target_aarch64_sve] } {
     set sve_flags "-march=armv8.2-a+sve"
 }
 
+# Turn off any codegen tweaks by default that may affect expected assembly.
+# Tests relying on those should turn them on explicitly.
+set sve_flags "$sve_flags -moverride=tune=none"
+
 # Main loop.
 set files [glob -nocomplain \
 	       "$srcdir/$subdir/general/*.c" \