[gcc(refs/users/aoliva/heads/testme)] testsuite: arm: restore defaults for multilib test

[Alexandre Oliva]

https://gcc.gnu.org/g:7c687d23913197a33fdc9aa67ba62062eef97103

commit 7c687d23913197a33fdc9aa67ba62062eef97103
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Wed Feb 4 23:50:28 2026 -0300

    testsuite: arm: restore defaults for multilib test
    
    When default-overriding options go in TOOL_OPTIONS, rather than in
    site.exp's cflags or multilib_flags, we don't skip multilib.exp, but
    those options may still interfere with multilib selection.
    
    Add cpu and fpu resetting-to-default options before multilib options
    under test, and set -mfloat-abi to a setting compatible with all
    combinations of options under test that don't override it.
    
    Arrange for -mfpu=* and -mfloat-abi=* options to negate each other,
    like -march and -mcpu, so that the overridden options are eliminated
    early on in prune_options, and don't affect multilib selection with
    conflicting choices.
    
    
    for  gcc/ChangeLog
    
            * gcc/config/arm/arm.opt (mfloat-abi=, mfpu=): Set Negative.
    
    for  gcc/testsuite/ChangeLog
    
            * gcc.target/arm/multilib.exp (check_multi_dir): Prepend
            default-resetting options.

Diff:
---
 gcc/config/arm/arm.opt                    | 4 ++--
 gcc/testsuite/gcc.target/arm/multilib.exp | 4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/gcc/config/arm/arm.opt b/gcc/config/arm/arm.opt
index e92a81312526..2a2239245d7b 100644
--- a/gcc/config/arm/arm.opt
+++ b/gcc/config/arm/arm.opt
@@ -115,7 +115,7 @@ Target Save RejectNegative Negative(mcpu=) ToLower Joined Var(arm_cpu_string)
 Specify the name of the target CPU.
 
 mfloat-abi=
-Target RejectNegative Joined Enum(float_abi_type) Var(arm_float_abi) Init(TARGET_DEFAULT_FLOAT_ABI)
+Target RejectNegative Negative(mfloat-abi=) Joined Enum(float_abi_type) Var(arm_float_abi) Init(TARGET_DEFAULT_FLOAT_ABI)
 Specify if floating point hardware should be used.
 
 mcmse
@@ -157,7 +157,7 @@ EnumValue
 Enum(arm_fp16_format_type) String(alternative) Value(ARM_FP16_FORMAT_ALTERNATIVE)
 
 mfpu=
-Target RejectNegative Joined Enum(arm_fpu) Var(arm_fpu_index) Init(TARGET_FPU_auto) Save
+Target RejectNegative Negative(mfpu=) Joined Enum(arm_fpu) Var(arm_fpu_index) Init(TARGET_FPU_auto) Save
 Specify the name of the target floating point hardware/format.
 
 mhard-float
diff --git a/gcc/testsuite/gcc.target/arm/multilib.exp b/gcc/testsuite/gcc.target/arm/multilib.exp
index b824173e7987..ea9baf4b0157 100644
--- a/gcc/testsuite/gcc.target/arm/multilib.exp
+++ b/gcc/testsuite/gcc.target/arm/multilib.exp
@@ -42,7 +42,9 @@ proc multilib_config {profile} {
 proc check_multi_dir { gcc_opts multi_dir } {
     global tool
 
-    set options [list "additional_flags=[concat "--print-multi-directory" $gcc_opts]"]
+    # Restore CPU, FPU and ABI defaults so that even if TOOL_OPTIONS
+    # set them, that won't affect our testing.
+    set options [list "additional_flags=[concat "--print-multi-directory -mcpu=unset -mfpu=auto -mfloat-abi=soft" $gcc_opts]"]
     set gcc_output [${tool}_target_compile "" "" "none" $options]
     if { [string match "$multi_dir\n" $gcc_output] } {
 	pass "multilibdir $gcc_opts $multi_dir"