testsuite: Fix up ext-floating{3,12}.C on i686-linux

These tests FAIL for quite a while on i686-linux since July last year,
likely r14-2628 .  Since that patch gcc claims _Float16 and __bf16
support even without -msse2 because some functions could be using
target attribute.
Later r14-2691 added -msse2 to add_options_for_float16, but didn't do that
for bfloat16, plus ext-floating{3,12}.C tests need the added dg-add-options,
so that float16 and bfloat16 effective targets match the __STDCPP_FLOAT16_T__
or __STDCPP_BFLOAT16_T__ macros.

Fixes
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++23  (test for errors, line 144)
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++23  (test for errors, line 146)
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++23  (test for errors, line 148)
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++23  (test for errors, line 150)
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++23  (test for errors, line 152)
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++23  (test for errors, line 154)
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++26  (test for errors, line 144)
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++26  (test for errors, line 146)
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++26  (test for errors, line 148)
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++26  (test for errors, line 150)
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++26  (test for errors, line 152)
-FAIL: g++.dg/cpp23/ext-floating12.C  -std=gnu++26  (test for errors, line 154)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++23  (test for errors, line 107)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++23  (test for errors, line 114)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++23  (test for errors, line 126)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++23  (test for errors, line 79)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++23  (test for errors, line 86)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++23  (test for errors, line 98)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++23  (test for warnings, line 22)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++23  (test for warnings, line 23)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++23  (test for warnings, line 24)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++23  (test for warnings, line 25)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++26  (test for errors, line 107)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++26  (test for errors, line 114)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++26  (test for errors, line 126)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++26  (test for errors, line 79)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++26  (test for errors, line 86)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++26  (test for errors, line 98)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++26  (test for warnings, line 22)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++26  (test for warnings, line 23)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++26  (test for warnings, line 24)
-FAIL: g++.dg/cpp23/ext-floating3.C  -std=gnu++26  (test for warnings, line 25)
on the latter and changes nothing on the former.

2024-03-27  Jakub Jelinek  <jakub@redhat.com>

	* lib/target-supports.exp (add_options_for_bfloat16): Add -msse2 on
	i?86/x86_64.
	* g++.dg/cpp23/ext-floating3.C: Add dg-add-options float16.
	* g++.dg/cpp23/ext-floating12.C: Add dg-add-options float16 and
	bfloat16.

3 files changed, 6 insertions, 0 deletions

diff --git a/gcc/testsuite/g++.dg/cpp23/ext-floating12.C b/gcc/testsuite/g++.dg/cpp23/ext-floating12.C
index 77ee4c7..a09c3fc 100644
--- a/gcc/testsuite/g++.dg/cpp23/ext-floating12.C
+++ b/gcc/testsuite/g++.dg/cpp23/ext-floating12.C
@@ -1,6 +1,8 @@
 // P1467R9 - Extended floating-point types and standard names.
 // { dg-do compile { target { c++23 && { i?86-*-linux* x86_64-*-linux* } } } }
 // { dg-options "" }
+// { dg-add-options float16 }
+// { dg-add-options bfloat16 }
 
 #include <complex>
 #include <stdfloat>
diff --git a/gcc/testsuite/g++.dg/cpp23/ext-floating3.C b/gcc/testsuite/g++.dg/cpp23/ext-floating3.C
index ca9399f..803a057 100644
--- a/gcc/testsuite/g++.dg/cpp23/ext-floating3.C
+++ b/gcc/testsuite/g++.dg/cpp23/ext-floating3.C
@@ -4,6 +4,7 @@
 // And some further tests.
 // { dg-do compile { target { c++23 && { i?86-*-linux* x86_64-*-linux* } } } }
 // { dg-options "" }
+// { dg-add-options float16 }
 
 #include "ext-floating.h"
 
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 3262104..843515f 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -3829,6 +3829,9 @@ proc check_effective_target_bfloat16_runtime {} {
 }
 
 proc add_options_for_bfloat16 { flags } {
+    if { [istarget i?86-*-*] || [istarget x86_64-*-*] } {
+	return "$flags -msse2"
+    }
     return "$flags"
 }