[Commit-gnuradio] [gnuradio] 01/09: volk: proposed solutions to bugs 582/583

[git]

This is an automated email from the git hooks/post-receive script.

jcorgan pushed a commit to branch maint
in repository gnuradio.

commit b5b53e70cb782a6f0190fdccb167311fe65be10f
Author: Nathan West <address@hidden>
Date:   Thu Jan 23 14:34:46 2014 -0600

    volk: proposed solutions to bugs 582/583
    
    582 and 583 are probably compiler bugs, and an upstream bug has been filed
    on launchpad with Linaro GCC. A static cast of the tolerance is not 
happening
    on armhf architectures. The work around forces a cast by using the values
    immediately after assignment.
---
 volk/lib/qa_utils.cc | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/volk/lib/qa_utils.cc b/volk/lib/qa_utils.cc
index 17164a4..9bf4b71 100644
--- a/volk/lib/qa_utils.cc
+++ b/volk/lib/qa_utils.cc
@@ -213,6 +213,19 @@ inline void run_cast_test3_s32fc(volk_fn_3arg_s32fc func, 
std::vector<void *> &b
     while(iter--) func(buffs[0], buffs[1], buffs[2], scalar, vlen, 
arch.c_str());
 }
 
+// This function is a nop that helps resolve GNU Radio bugs 582 and 583.
+// Without this the cast in run_volk_tests for tol_i = static_cast<int>(float 
tol)
+// won't happen on armhf (reported on cortex A9 and A15).
+void lv_force_cast_hf( int tol_i, float tol_f)
+{
+    int diff_i = 1;
+    float diff_f = 1;
+    if( diff_i > tol_i )
+        std::cout << "" ;
+    if( diff_f > tol_f )
+        std::cout << "" ;
+}
+
 template <class t>
 bool fcompare(t *in1, t *in2, unsigned int vlen, float tol) {
     bool fail = false;
@@ -269,8 +282,15 @@ bool run_volk_tests(volk_func_desc_t desc,
                    ) {
     std::cout << "RUN_VOLK_TESTS: " << name << std::endl;
 
-    const float tol_f = tol;
-    const unsigned int tol_i = static_cast<unsigned int>(tol);
+    // The multiply and lv_force_cast_hf are work arounds for GNU Radio bugs 
582 and 583
+    // The bug is the casting/assignment below do not happen, which results in 
false
+    // positives when testing for errors in fcompare and icompare.
+    // Since this only happens on armhf (reported for Cortex A9 and A15) 
combined with
+    // the following fixes it is suspected to be a compiler bug. 
+    // Bug 1272024 on launchpad has been filed with Linaro GCC.
+    const float tol_f = tol*1.0000001;
+    const unsigned int tol_i = static_cast<const unsigned int>(tol);
+    lv_force_cast_hf( tol_i, tol_f );
 
     //first let's get a list of available architectures for the test
     std::vector<std::string> arch_list = get_arch_list(desc);