| Message ID | 68d7c42c-3ebe-532b-6403-63f8975d97d2@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | RFA: patch for test PR70669 test | expand |
Hi! On Thu, Nov 22, 2018 at 02:47:10PM -0500, Vladimir Makarov wrote: > Today I committed a patch > > https://gcc.gnu.org/ml/gcc-patches/2018-11/msg01945.html > > But it makes gcc.target/powerpc/pr70669.c to fail. Here is the patch > to fix the failure. The expected code assumes that variable r should > get a general reg. I suspect the expectation is wrong. There are three > possible choices for r: a general reg, a vsx reg, and memory. > > The cost of move of vsx to/from mem is 4, the cost of move of general > reg of this mode to/from mem is 8, and the cost of move of general reg > to/from vsx is 12. > > So approximately if r is assigned memory we have cost 8 * 2 (asm) + 4 > * 2 (plus) = 24 (when we use memory at *q), if r is assigned to vsx the > cost is 12*2(asm) + 4(r=*q) = 28, and if r is assigned a general reg the > cost is 12 * 2 (plus) + 8 (r = *q) = 32. > > ira-costs should choose mem although it chose a general reg before my > patch (it is a big topic why it chose a general reg. In brief, it is > because some inherent drawbacks of the current cost calculation > algorithm). The patch I recently submitted solves some drawbacks and > memory is chosen for r. That sounds all correct. Thanks for fixing this! > To generate the expected code with r in a general reg, I just decrease > the number of getting r value into vsx reg by changing r + r onto -r. > > Is the following patch ok for trunk? Yes, the test now again tests what it is meant to test (that you get m[tf]vsrd from reloads). It's fine for trunk, thanks! Segher 2018-11-22 Vladimir Makarov <vmakarov@redhat.com> * gcc.target/powerpc/pr70669.c: Use unary minus instead of addition.
On 11/22/2018 07:30 PM, Segher Boessenkool wrote: > Hi! > > On Thu, Nov 22, 2018 at 02:47:10PM -0500, Vladimir Makarov wrote: > >> To generate the expected code with r in a general reg, I just decrease >> the number of getting r value into vsx reg by changing r + r onto -r. >> >> Is the following patch ok for trunk? > Yes, the test now again tests what it is meant to test (that you get > m[tf]vsrd from reloads). It's fine for trunk, thanks! > > Thank you, Segher. Committed as rev. 266421.
Index: testsuite/ChangeLog =================================================================== --- testsuite/ChangeLog (revision 266318) +++ testsuite/ChangeLog (working copy) @@ -1,3 +1,8 @@ +2018-11-22 Vladimir Makarov <vmakarov@redhat.com> + + * gcc.target/powerpc/pr70669.c: Use unary minus instead of + addition. + 2018-11-20 Jan Hubicka <hubicka@ucw.cz> PR ipa/87706 Index: testsuite/gcc.target/powerpc/pr70669.c =================================================================== --- testsuite/gcc.target/powerpc/pr70669.c (revision 266318) +++ testsuite/gcc.target/powerpc/pr70669.c (working copy) @@ -13,7 +13,7 @@ void foo (TYPE *p, TYPE *q) #ifndef NO_ASM __asm__ (" # %0" : "+r" (r)); #endif - *p = r + r; + *p = -r; } /* { dg-final { scan-assembler "mfvsrd" } } */