Anton Blanchard found that in some cases, setting V4SImode and V8HImode vector registers to all 0's or all 1's could cause the compiler issue an 'insn does not satisfy its constraints' error message. The reason was, 0/-1 treated specially, since we can generate them using normal ISA 2.06/2.07 instructions. I added an alternative, to allow these constants for ISA 3.0.
I did a bootstrap and make check with no regressions on a little endian power8, and I have a similar run going on a big endian power7 system. Assuming the power7 system also had no regressions, is this ok to install in the trunk, and back ported to GCC 6.2 when the previous ISA 3.0 patches get back ported. [gcc] 2016-05-31 Michael Meissner <meiss...@linux.vnet.ibm.com> PR target/71186 * config/rs6000/vsx.md (xxspltib_<mode>_nosplit): Add alternatives for loading up all 0's or all 1's. [gcc/testsuite] 2016-05-31 Michael Meissner <meiss...@linux.vnet.ibm.com> PR target/71186 * gcc.target/powerpc/pr71186.c: New test. -- Michael Meissner, IBM IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA email: meiss...@linux.vnet.ibm.com, phone: +1 (978) 899-4797
Index: gcc/config/rs6000/vsx.md =================================================================== --- gcc/config/rs6000/vsx.md (.../svn+ssh://meiss...@gcc.gnu.org/svn/gcc/trunk/gcc/config/rs6000) (revision 236935) +++ gcc/config/rs6000/vsx.md (.../gcc/config/rs6000) (working copy) @@ -776,8 +776,8 @@ (define_insn "xxspltib_v16qi" [(set_attr "type" "vecperm")]) (define_insn "xxspltib_<mode>_nosplit" - [(set (match_operand:VSINT_842 0 "vsx_register_operand" "=wa") - (match_operand:VSINT_842 1 "xxspltib_constant_nosplit" "wE"))] + [(set (match_operand:VSINT_842 0 "vsx_register_operand" "=wa,wa") + (match_operand:VSINT_842 1 "xxspltib_constant_nosplit" "jwM,wE"))] "TARGET_P9_VECTOR" { rtx op1 = operands[1]; Index: gcc/testsuite/gcc.target/powerpc/pr71186.c =================================================================== --- gcc/testsuite/gcc.target/powerpc/pr71186.c (revision 0) +++ gcc/testsuite/gcc.target/powerpc/pr71186.c (revision 0) @@ -0,0 +1,32 @@ +/* { dg-do compile { target { powerpc64*-*-* && lp64 } } } */ +/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } { "-mcpu=power9" } } */ +/* { dg-options "-mcpu=power9 -O2" } */ +/* { dg-require-effective-target powerpc_p9vector_ok } */ + +static unsigned short x[(16384/sizeof(unsigned short))] __attribute__ ((aligned (16))); +static unsigned short y[(16384/sizeof(unsigned short))] __attribute__ ((aligned (16))); +static unsigned short a; + +void obfuscate(void *a, ...); + +static void __attribute__((noinline)) do_one(void) +{ + unsigned long i; + + obfuscate(x, y, &a); + + for (i = 0; i < (16384/sizeof(unsigned short)); i++) + y[i] = a * x[i]; + + obfuscate(x, y, &a); +} + +int main(void) +{ + unsigned long i; + + for (i = 0; i < 1000000; i++) + do_one(); + + return 0; +}