[glibc] C-SKY: Make dynamic linker's name compitable with the older gcc.

[Han Mao <maohan@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=56b223c1c8334e4255bf11aed1386a007822702a

commit 56b223c1c8334e4255bf11aed1386a007822702a
Author: Cooper Qu <cooper.qu@linux.alibaba.com>
Date:   Tue Oct 20 23:00:59 2020 +0800

    C-SKY: Make dynamic linker's name compitable with the older gcc.
    
    __CSKY_HARD_FLOAT_ABI__ was added on gcc 11 to specify whether
    -mfloat-abi=hard is set.  On older gcc, the float ABI is defined
    solely with __CSKY_HARD_FLOAT__.  If __CSKY_HARD_FLOAT__ is set, it can
    be either a hard-float ABI (gcc older than 11, or gcc11 -mfloat-abi=hard
    (__CSKY_HARD_FLOAT_ABI__ is set) or -mfloat-abi=softfp
    (__CSKY_HARD_FLOAT_ABI__ is not set). To be compatible with older gcc,
    use __CSKY_HARD_FLOAT_FPU_SF__ identify if -mfloat-abi is supported,
    because it is added to gcc at the same time as -mfloat-abi.
    
    Reviewed-by: Mao Han  <han_mao@linux.alibaba.com>
    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

Diff:
---
 sysdeps/csky/preconfigure | 35 ++++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/sysdeps/csky/preconfigure b/sysdeps/csky/preconfigure
index 16f3b60cf5..5f22416f95 100644
--- a/sysdeps/csky/preconfigure
+++ b/sysdeps/csky/preconfigure
@@ -2,8 +2,12 @@ case "$machine" in
 csky*)
     abi=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null |
       sed -n 's/^#define __CSKYABI__ \(.*\)/\1/p'`
-    float_abi=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null |
+    hard_float=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null |
       sed -n 's/^#define __CSKY_HARD_FLOAT__ \(.*\)/\1/p'`
+    hard_float_sf=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null |
+      sed -n 's/^#define __CSKY_HARD_FLOAT_FPU_SF__ \(.*\)/\1/p'`
+    hard_float_abi=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null |
+      sed -n 's/^#define __CSKY_HARD_FLOAT_ABI__ \(.*\)/\1/p'`
 
     case "$abi" in
     1)
@@ -19,14 +23,27 @@ csky*)
         ;;
     esac
 
-    case "$float_abi" in
-    1)
-        with_fp_cond=1
-        ;;
-    *)
-        with_fp_cond=0
-        ;;
-    esac
+    # __CSKY_HARD_FLOAT_ABI__ was added on gcc 11 to specify whether
+    # -mfloat-abi=hard is set.  On older gcc, the float ABI is defined solely
+    # with __CSKY_HARD_FLOAT__.  If __CSKY_HARD_FLOAT__ is set, it can be
+    # either a hard-float ABI (gcc older than 11, or gcc11 -mfloat-abi=hard
+    # (__CSKY_HARD_FLOAT_ABI__ is set) or -mfloat-abi=softfp
+    # (__CSKY_HARD_FLOAT_ABI__ is not set). To be compatible with older gcc,
+    # use __CSKY_HARD_FLOAT_FPU_SF__ identify if -mfloat-abi is supported,
+    # because it is added to gcc at the same time as -mfloat-abi.
+    if test -n "$hard_float"; then
+	if test -z "$hard_float_sf"; then
+	    with_fp_cond=1
+	else
+	    if test -n "$hard_float_abi"; then
+		with_fp_cond=1
+	    else
+		with_fp_cond=0
+	    fi
+	fi
+    else
+	with_fp_cond=0
+    fi
 
     base_machine=csky
     machine=csky/$machine