[gcc(refs/vendors/ARM/heads/arm-perf-staging)] aarch64: Add an extra comment to arm_sve.h

[Tamar Christina]

https://gcc.gnu.org/g:c508fd07d7615443f7a62d6745779ec97514e7a2

commit c508fd07d7615443f7a62d6745779ec97514e7a2
Author: Richard Sandiford <richard.sandiford@arm.com>
Date:   Fri Apr 24 11:58:19 2020 +0100

    aarch64: Add an extra comment to arm_sve.h
    
    I've had a couple of conversations now in which the shortness
    of arm_sve.h was causing confusion, with people thinking that
    the types and intrinsics were missing.  It seems worth adding
    a comment to explain what's going on.
    
    2020-04-24  Richard Sandiford  <richard.sandiford@arm.com>
    
    gcc/
            * config/aarch64/arm_sve.h: Add a comment.

Diff:
---
 gcc/ChangeLog                | 4 ++++
 gcc/config/aarch64/arm_sve.h | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6032e681d7f..d402ae643d3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2020-04-24  Richard Sandiford  <richard.sandiford@arm.com>
+
+	* config/aarch64/arm_sve.h: Add a comment.
+
 2020-04-24  Haijian Zhang <z.zhanghaijian@huawei.com>
 
 	PR rtl-optimization/94708
diff --git a/gcc/config/aarch64/arm_sve.h b/gcc/config/aarch64/arm_sve.h
index f2d2d0ce9aa..5cad9a4cb2e 100644
--- a/gcc/config/aarch64/arm_sve.h
+++ b/gcc/config/aarch64/arm_sve.h
@@ -32,6 +32,11 @@ typedef __fp16 float16_t;
 typedef float float32_t;
 typedef double float64_t;
 
+/* NOTE: This implementation of arm_sve.h is intentionally short.  It does
+   not define the SVE types and intrinsic functions directly in C and C++
+   code, but instead uses the following pragma to tell GCC to insert the
+   necessary type and function definitions itself.  The net effect is the
+   same, and the file is a complete implementation of arm_sve.h.  */
 #pragma GCC aarch64 "arm_sve.h"
 
 #endif