* Balbir Singh [off-list ref] [2016-02-11 18:48:17]:

On Wed, 2016-02-10 at 17:25 +0100, Torsten Duwe wrote:

snip

quoted

diff --git a/arch/powerpc/gcc-mprofile-kernel-notrace.sh b/arch/powerpc/gcc-mprofile-kernel-notrace.sh
new file mode 100755
index 0000000..68d6482
--- /dev/null
+++ b/arch/powerpc/gcc-mprofile-kernel-notrace.sh

@@ -0,0 +1,33 @@
+#!/bin/sh
+# Test whether the compile option -mprofile-kernel
+# generates profiling code ( = a call to mcount), and
+# whether a function without any global references sets
+# the TOC pointer properly at the beginning, and
+# whether the "notrace" function attribute successfully
+# suppresses the _mcount call.
+
+echo "int func() { return 0; }" | \
+    $* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null | \
+    grep -q "mcount"
+
+trace_result=$?
+
+echo "int func() { return 0; }" | \
+    $* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null | \
+    sed -n -e '/func:/,/bl _mcount/p' | grep -q TOC
+
+leaf_toc_result=$?
+

leaf_toc_result failed for me with gcc 5. I'll try and grab gcc-6
and give the patches a spin

It fails for me to on ppc64le but pass over ppc64

# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/ppc64-redhat-linux/5.1.1/lto-wrapper
Target: ppc64-redhat-linux
[...]
gcc version 5.1.1 20150422 (Red Hat 5.1.1-1) (GCC)

# echo "int func() { return 0;  }" |     gcc -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null |     sed -n -e '/func:/,/bl _mcount/p'
func:
        .quad   .L.func,.TOC.@tocbase
        .previous
        .type   func, @function
.L.func:
        mflr 0
        std 0,16(1)
        bl _mcount

# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/powerpc64le-linux-gnu/5/lto-wrapper
Target: powerpc64le-linux-gnu
[...]
gcc version 5.3.1 20160205 (Ubuntu/IBM 5.3.1-8ubuntu2)

# echo "int func() { return 0;  }" |     gcc -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null |     sed -n -e '/func:/,/bl _mcount/p'
func:
        mflr 0
        std 0,16(1)
        bl _mcount


I will try it over gcc-6.

Thanks,
Kamalesh