Bug 401827

Summary: none/tests/ppc64/test_isa_2_06_part3 failure on ppc64le (xvrsqrtesp)
Product: [Developer tools] valgrind Reporter: Mark Wielaard <mark>
Component: generalAssignee: Julian Seward <jseward>
Status: CLOSED FIXED    
Severity: normal CC: cel, will_schmidt
Priority: NOR    
Version: unspecified   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Mark Wielaard 2018-12-06 15:11:01 UTC 
none/tests/ppc64/test_isa_2_06_part3.stdout.diff shows:

--- test_isa_2_06_part3.stdout.exp      2018-12-06 10:04:10.500178317 -0500
+++ test_isa_2_06_part3.stdout.out      2018-12-06 10:04:16.229937222 -0500
@@ -59,8 +59,8 @@
 
 #0: xvrsqrtesp 1/x-sqrt(3ec00000) ==> PASS); 1/x-sqrt(42780000) ==> PASS); 1/x-sqrt(00000000) ==> PASS); 1/x-sqrt(7f800000) ==> PASS)
 #1: xvrsqrtesp 1/x-sqrt(00000000) ==> PASS); 1/x-sqrt(00000000) ==> PASS); 1/x-sqrt(80000000) ==> PASS); 1/x-sqrt(7f800000) ==> PASS)
-#2: xvrsqrtesp 1/x-sqrt(ff800000) ==> PASS); 1/x-sqrt(7fbfffff) ==> PASS); 1/x-sqrt(ffbfffff) ==> PASS); 1/x-sqrt(7fc00000) ==> PASS)
-#3: xvrsqrtesp 1/x-sqrt(ffc00000) ==> PASS); 1/x-sqrt(80000000) ==> PASS); 1/x-sqrt(c683287b) ==> PASS); 1/x-sqrt(49192c2d) ==> PASS)
+#2: xvrsqrtesp 1/x-sqrt(ff800000) ==> FAIL); 1/x-sqrt(7fbfffff) ==> PASS); 1/x-sqrt(ffbfffff) ==> PASS); 1/x-sqrt(7fc00000) ==> PASS)
+#3: xvrsqrtesp 1/x-sqrt(ffc00000) ==> PASS); 1/x-sqrt(80000000) ==> PASS); 1/x-sqrt(c683287b) ==> FAIL); 1/x-sqrt(49192c2d) ==> PASS)
 #4: xvrsqrtesp 1/x-sqrt(49c1288d) ==> PASS); 1/x-sqrt(418977ad) ==> PASS); 1/x-sqrt(428a5faf) ==> PASS); 1/x-sqrt(44bb5fcc) ==> PASS)
 
 #0: xvsqrtdp sqrt(3fd8000000000000) = 3fe3988e1409212e; sqrt(404f000000000000) = 401f7efbeb8d4f12

This is with gcc-8.2.1-3.4.el8.ppc64le, glibc-2.28-39.el8.ppc64le and binutils-2.30-49.el8.ppc64le
Comment 1 Will Schmidt 2019-01-09 18:23:04 UTC 
At first blush, behaviour here is similar to what is being seen in 401828 (valgrind, errors with isa_2_06_part1 test).
Net is that the testcase fails under valgrind when a newer gcc is used to build it.    Test runs OK outside of valgrind.   Test runs OK under valgrind if the test is built with -O0.
Comment 2 Carl Love 2019-04-04 17:36:01 UTC 
I reviewed and tested the attached patch to fix this issue.  The patch fixes this bug and bugzilla 401828.  The patch was tested on Power 7, Power 8 LE, Power 8 BE, Power 9.

The patch commit:

commit 82e94fff802aece376d5ca8458ef49d24afd7bdf
Author: Carl Love <carll@us.ibm.com>
Date:   Thu Apr 4 12:31:05 2019 -0500

    PPC64, patch to test case issues reported in bugzilla 401827 and 401828.