On 1/27/25 12:48 PM, Vineet Gupta wrote:
On 1/26/25 05:29, Jeff Law wrote:
On 1/24/25 3:12 PM, Vineet Gupta wrote:
RV-Vector FP-INT insns use the rounding mode in FRM register which if
explicitly set for V insn needs, is saved/restored (although from the
psABI CC Spec, it is not clear if it actually a caller-saved or
callee-saved).
Anyhow in the failure case the save/restore were generated by the
Mode Switch pass, but then eliminated by sched1:DCE and Late-Combine.
Fix this by using unspec_volatile variant which won't be eliminated.
This showed up as SPEC2017 527.cam4 runtime aborts in glibc:round_away()
which checks for standard rounding modes and the "leaking" rounding mode
due to the bug happened to be a non-standard RISC-V specific RMM
"Round to Nearest, ties to Max".
This is testsuite clean:
Not sure how it could be clean as I think the test itself is busted ;-)
Sorry for the snafu; I would blame "send the patch out on friday" that bit me.
I used the raw test for debugging and coming up with the fix, but before
integrating the test properly I ran the existing testsuite w/ my patch and made
sure it didn't regress anything, so those test results are for real minus the
new test.
It happens. I had a goof of similar nature trying to get something out
the door last week as well :-)
What I wanted to do was use your testcase with Pan's patch to see if
Pan's patch resolved both issues.
Yes it does.
Your compiler patch may still be desirable as well, I really haven't
really evaluated that yet.
FWIW with Pan's rework the need for volatile goes away anyways.
The fixed up test (actually tested for A/B pass/fail) which can be integrated in
Pan's commit can be found below
If you could go ahead and install the test into the testsuite, it'd be
appreciated.
Thanks!
jeff
