Re: [testsuite] skip ARM neon-fp16 tests for other -mcpu values

[Janis Johnson <janisjo@codesourcery.com>]

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On 06/15/2011 05:53 AM, Richard Earnshaw wrote:
> On 10/06/11 00:43, Janis Johnson wrote:
>> On 06/08/2011 03:17 AM, Joseph S. Myers wrote:
>>> On Tue, 7 Jun 2011, Janis Johnson wrote:
>>>
>>>> These tests fail when multilib options use -mfpu=xxxx and override the
>>>> -mfpu=neon-fp16 used for the test:
>>>>
>>>>   g++.dg/ext/arm-fp16/arm-fp16-ops-5.C
>>>>   g++.dg/ext/arm-fp16/arm-fp16-ops-6.C
>>>>   gcc.dg/torture/arm-fp16-ops-5.c
>>>>   gcc.dg/torture/arm-fp16-ops-6.c
>>>>   gcc.target/arm/fp16-compile-vcvt.c
>>>>
>>>> The option -mfpu-neon-fp16 is added via "dg-add-options arm_neon_fp16"
>>>> after an earlier "dg-require-effective-target arm_neon_fp16_ok".
>>>> This patch modifies check_effective_target_arm_neon_fp16_ok_nocache to
>>>> return 0 (causing the test to be skipped) if multilib flags include
>>>> -mfpu= with a value other than neon-fp16.
>>>
>>> But I'd think they ought to work with any -mfpu= option supporting 
>>> half-precision instructions - that is, vfpv3-fp16, vfpv3-d16-fp16, 
>>> vfpv3xd-fp16, neon-fp16, vfpv4, vfpv4-d16, fpv4-sp-d16, neon-vfpv4 
>>> (anything with "true" in the last field in arm-fpus.def; for the 
>>> testsuite, you can probably suppose anything -mfpu=*fp16*, 
>>> -mfpu=*fpv[4-9]*, -mfpu=*fpv[1-9][0-9]*).
>>>
>>
>> These tests look for specific instructions being generated and fail when
>> the check is hacked up to allow other fp16 variants and not require neon.
>> I'd like to use the original patch for this.  OK?
>>
>> Janis
> 
> That sounds like you might have uncovered a bug.  Can you provide some
> more detail?
> 
> Running (manually) gcc.target/arm/fp16-compile-vcvt.c with "-O
> -mfpu=vfpv4 -mfp16-format=ieee" gives the instructions required by the
> scanner.
> 
> R.

The bug was in my attempt to run the tests with other -mfpu values, so
I'm very glad you caught that.  I tried again, getting rid of the neon
requirement along the way, and found a way to run the VFP fp16 tests
with any of the fp16 values that Joseph listed.

This patch renames *arm_neon_fp16* to *arm_fp16* and skips tests if the
multilib does not support arm32, includes -mfpu that is not fp16, or
includes -mfloat-abi=soft.  If the multilib uses -mfpu= with an fp16
value then that is used, otherwise -mfpu=vfpv4 is used.  Added flags
include -mfloat-abi=softfp in case the default is "soft".

Tested on arm-none-linux-gnueabi with multilib test flags (not actual
runtime support) for each -march value and each fp16 -mfpu value.

OK for trunk, and for 4.6 a few days later?

Janis


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2011-06-15  Janis Johnson  <janisjo@codesourcery.com>

	* lib/target-supports.exp (add_options_for_arm_fp16): Renamed
	from add_options_for_arm_neon_fp16.
	(check_effective_target_arm_fp16_ok_nocache): Renamed from
	check_effective_target_arm_neon_fp16_ok_nocache.
	Check -mfpu and -mfloat-abi options from current multilib.
	Do not require neon support.
	(check_effective_target_arm_fp16_ok): Renamed from
	check_effecitve_target_arm_neon_fp16_ok.
	* g++.dg/ext/arm-fp16/arm-fp16-ops-5.C: Use new names for
	arm_neon_fp16_ok and arm_fp16.
	* g++.dg/ext/arm-fp16/arm-fp16-ops-6.C: Likewise.
	* gcc.dg/torture/arm-fp16-ops-5.c: Likewise.
	* gcc.dg/torture/arm-fp16-ops-6.c: Likewise.
	* gcc.target/arm/fp16-compile-vcvt.c: Likewise.

Index: lib/target-supports.exp
===================================================================
--- lib/target-supports.exp	(revision 175083)
+++ lib/target-supports.exp	(working copy)
@@ -1947,45 +1947,53 @@
 # or -mfloat-abi=hard, but if one is already specified by the
 # multilib, use it.
 
-proc add_options_for_arm_neon_fp16 { flags } {
-    if { ! [check_effective_target_arm_neon_fp16_ok] } {
+proc add_options_for_arm_fp16 { flags } {
+    if { ! [check_effective_target_arm_fp16_ok] } {
 	return "$flags"
     }
-    global et_arm_neon_fp16_flags
-    return "$flags $et_arm_neon_fp16_flags"
+    global et_arm_fp16_flags
+    return "$flags $et_arm_fp16_flags"
 }
 
-# Return 1 if this is an ARM target supporting -mfpu=neon-fp16
-# -mfloat-abi=softfp or equivalent options.  Skip multilibs that are
-# incompatible with these options.  Also set et_arm_neon_flags to the
-# best options to add.
+# Return 1 if this is an ARM target that can support a VFP fp16 variant.
+# Skip multilibs that are incompatible with these options and set
+# et_arm_fp16_flags to the best options to add.
 
-proc check_effective_target_arm_neon_fp16_ok_nocache { } {
-    global et_arm_neon_fp16_flags
-    set et_arm_neon_fp16_flags ""
-    if { [check_effective_target_arm32] } {
-	if [check-flags [list "" { *-*-* } { "-mfpu=*" } { "-mfpu=neon-fp16*" } ]] {
-	    return 0
-	}
-	# Always add -mfpu=neon-fp16, since there is no preprocessor
-	# macro for FP16 support.
-	foreach flags {"-mfpu=neon-fp16" "-mfpu=neon-fp16 -mfloat-abi=softfp"} {
-	    if { [check_no_compiler_messages_nocache arm_neon_fp16_ok object {
-		#include "arm_neon.h"
-		int dummy;
-	    } "$flags"] } {
-		set et_arm_neon_fp16_flags $flags
-		return 1
-	    }
-	}
+proc check_effective_target_arm_fp16_ok_nocache { } {
+    global et_arm_fp16_flags
+    set et_arm_fp16_flags ""
+    if { ! [check_effective_target_arm32] } {
+	return 0;
     }
+    if [check-flags [list "" { *-*-* } { "-mfpu=*" } { "-mfpu=*fp16*" "-mfpu=*fpv[4-9]*" "-mfpu=*fpv[1-9][0-9]*" } ]] {
+	# Multilib flags would override -mfpu.
+	return 0
+    }
+    if [check-flags [list "" { *-*-* } { "-mfloat-abi=soft" } { "" } ]] {
+	# Must generate floating-point instructions.
+	return 0
+    }
+    if [check-flags [list "" { *-*-* } { "-mfpu=*" } { "" } ]] {
+        # The existing -mfpu value is OK; use it, but add softfp.
+	set et_arm_fp16_flags "-mfloat-abi=softfp"
+	return 1;
+    }
+    # Add -mfpu for a VFP fp16 variant since there is no preprocessor
+    # macro to check for this support.
+    set flags "-mfpu=vfpv4 -mfloat-abi=softfp"
+    if { [check_no_compiler_messages_nocache arm_fp16_ok assembly {
+	int dummy;
+    } "$flags"] } {
+	set et_arm_fp16_flags "$flags"
+	return 1
+    }
 
     return 0
 }
 
-proc check_effective_target_arm_neon_fp16_ok { } {
-    return [check_cached_effective_target arm_neon_fp16_ok \
-		check_effective_target_arm_neon_fp16_ok_nocache]
+proc check_effective_target_arm_fp16_ok { } {
+    return [check_cached_effective_target arm_fp16_ok \
+		check_effective_target_arm_fp16_ok_nocache]
 }
 
 # Return 1 is this is an ARM target where -mthumb causes Thumb-1 to be
Index: g++.dg/ext/arm-fp16/arm-fp16-ops-5.C
===================================================================
--- g++.dg/ext/arm-fp16/arm-fp16-ops-5.C	(revision 175083)
+++ g++.dg/ext/arm-fp16/arm-fp16-ops-5.C	(working copy)
@@ -1,8 +1,8 @@
 /* Test various operators on __fp16 and mixed __fp16/float operands.  */
 /* { dg-do compile { target arm*-*-* } } */
-/* { dg-require-effective-target arm_neon_fp16_ok } */
+/* { dg-require-effective-target arm_fp16_ok } */
 /* { dg-options "-mfp16-format=ieee" } */
-/* { dg-add-options arm_neon_fp16 } */
+/* { dg-add-options arm_fp16 } */
 
 #include "arm-fp16-ops.h"
 
Index: g++.dg/ext/arm-fp16/arm-fp16-ops-6.C
===================================================================
--- g++.dg/ext/arm-fp16/arm-fp16-ops-6.C	(revision 175083)
+++ g++.dg/ext/arm-fp16/arm-fp16-ops-6.C	(working copy)
@@ -1,8 +1,8 @@
 /* Test various operators on __fp16 and mixed __fp16/float operands.  */
 /* { dg-do compile { target arm*-*-* } } */
-/* { dg-require-effective-target arm_neon_fp16_ok } */
+/* { dg-require-effective-target arm_fp16_ok } */
 /* { dg-options "-mfp16-format=ieee -ffast-math" } */
-/* { dg-add-options arm_neon_fp16 } */
+/* { dg-add-options arm_fp16 } */
 
 #include "arm-fp16-ops.h"
 
Index: gcc.dg/torture/arm-fp16-ops-5.c
===================================================================
--- gcc.dg/torture/arm-fp16-ops-5.c	(revision 175083)
+++ gcc.dg/torture/arm-fp16-ops-5.c	(working copy)
@@ -1,8 +1,8 @@
 /* Test various operators on __fp16 and mixed __fp16/float operands.  */
 /* { dg-do compile { target arm*-*-* } } */
-/* { dg-require-effective-target arm_neon_fp16_ok } */
+/* { dg-require-effective-target arm_fp16_ok } */
 /* { dg-options "-mfp16-format=ieee" } */
-/* { dg-add-options arm_neon_fp16 } */
+/* { dg-add-options arm_fp16 } */
 
 #include "arm-fp16-ops.h"
 
Index: gcc.dg/torture/arm-fp16-ops-6.c
===================================================================
--- gcc.dg/torture/arm-fp16-ops-6.c	(revision 175083)
+++ gcc.dg/torture/arm-fp16-ops-6.c	(working copy)
@@ -1,8 +1,8 @@
 /* Test various operators on __fp16 and mixed __fp16/float operands.  */
 /* { dg-do compile { target arm*-*-* } } */
-/* { dg-require-effective-target arm_neon_fp16_ok } */
+/* { dg-require-effective-target arm_fp16_ok } */
 /* { dg-options "-mfp16-format=ieee -ffast-math" } */
-/* { dg-add-options arm_neon_fp16 } */
+/* { dg-add-options arm_fp16 } */
 
 #include "arm-fp16-ops.h"
 
Index: gcc.target/arm/fp16-compile-vcvt.c
===================================================================
--- gcc.target/arm/fp16-compile-vcvt.c	(revision 175083)
+++ gcc.target/arm/fp16-compile-vcvt.c	(working copy)
@@ -1,7 +1,7 @@
 /* { dg-do compile } */
-/* { dg-require-effective-target arm_neon_fp16_ok } */
+/* { dg-require-effective-target arm_fp16_ok } */
 /* { dg-options "-mfp16-format=ieee" } */
-/* { dg-add-options arm_neon_fp16 } */
+/* { dg-add-options arm_fp16 } */
 
 /* Test generation of VFP __fp16 instructions.  */