[PATCH] arm: Improve documentation for effective target 'arm_softfloat'

[Andrea Corallo]

Hi all,

I'd like to submit the following patch to better specify the meaning
of the 'arm_softfloat' effective target.

As I've recently discovered we can have cases where '-mfloat-abi=hard'
is used and the compiler correctly defines '__SOFTFP__'.

Effectively 'arm_softfloat' is checking if the target requires floating
point emulation but not what ABI is used, so I think would be nice to
specify that in the documentation.

Okay for trunk?

Thanks

  Andrea
  
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>From 67e74689e4332d33c3f27119dc21a7722bb6125b Mon Sep 17 00:00:00 2001
From: Andrea Corallo <andrea.corallo@arm.com>
Date: Tue, 1 Dec 2020 11:21:33 +0100
Subject: [PATCH] arm: Improve documentation for effective target
 'arm_softfloat'

gcc/ChangeLog

2020-12-01  Andrea Corallo  <andrea.corallo@arm.com>

	* doc/sourcebuild.texi (arm_softfloat): Improve documentation.

gcc/testsuite/ChangeLog

2020-12-01  Andrea Corallo  <andrea.corallo@arm.com>

	* lib/target-supports.exp (check_effective_target_arm_softfloat):
	Improve documentation.
---
 gcc/doc/sourcebuild.texi              | 3 +--
 gcc/testsuite/lib/target-supports.exp | 4 ++--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index 852eaa2e676..72b83748318 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -1799,8 +1799,7 @@ variant of the ABI for the ARM Architecture (as selected with
 @code{-mfloat-abi=hard}).
 
 @item arm_softfloat
-ARM target uses the soft-float ABI with no floating-point instructions
-used whatsoever (as selected with @code{-mfloat-abi=soft}).
+ARM target uses emulated floating point operations.
 
 @item arm_hard_vfp_ok
 ARM target supports @code{-mfpu=vfp -mfloat-abi=hard}.
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index ff6bc5f4b92..24ff9fa0476 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -5658,8 +5658,8 @@ proc check_effective_target_arm_hf_eabi { } {
     }]
 }
 
-# Return 1 if this is an ARM target that uses the soft float ABI
-# with no floating-point instructions at all (e.g. -mfloat-abi=soft).
+# Return 1 if this is an ARM target uses emulated floating point
+# operations.
 
 proc check_effective_target_arm_softfloat { } {
     return [check_no_compiler_messages arm_softfloat object {
-- 
2.20.1