This patch fixes an error in the code generation for vec_pack (vector double, vector double). As previously implemented, this built-in function translates to the vpkudum instruction.
This patch causes vec_pack (vector double, vector double) to behave the same as vec_float2 for the same type signature, producing the vmrgow instruction on little-endian targets and the vmrgew instruction on big-endian targets. This revision differs from the initial path submission in that it combines all of the new testing into two test programs, using target qualifiers on the dg scan-assembler-times directives. This patch has bootstrapped and tested without regressions on powerpc64le-unknown-linux (both P8 and P9) and on powerpc-linux (P8 big-endian, both -m32 and -m64). Is this ok for the trunk? gcc/ChangeLog: 2018-06-19 Kelvin Nilsen <kel...@gcc.gnu.org> * config/rs6000/rs6000-c.c (altivec_overloaded_builtins): Change behavior of vec_pack (vector double, vector double) to match behavior of vec_float2 (vector double, vector double). gcc/testsuite/ChangeLog: 2018-06-19 Kelvin Nilsen <kel...@gcc.gnu.org> * gcc.target/powerpc/builtins-3-p8.c (test_pack_float): Remove this test. * gcc.target/powerpc/builtins-9.c: New test. * gcc.target/powerpc/fold-vec-pack-double.c: Modify dg directives to expect different code generation on big-endian vs. little-endian targets. Index: gcc/config/rs6000/rs6000-c.c =================================================================== --- gcc/config/rs6000/rs6000-c.c (revision 261341) +++ gcc/config/rs6000/rs6000-c.c (working copy) @@ -2425,7 +2425,7 @@ const struct altivec_builtin_types altivec_overloa RS6000_BTI_unsigned_V4SI, RS6000_BTI_unsigned_V2DI, RS6000_BTI_unsigned_V2DI, 0 }, { ALTIVEC_BUILTIN_VEC_PACK, P8V_BUILTIN_VPKUDUM, RS6000_BTI_bool_V4SI, RS6000_BTI_bool_V2DI, RS6000_BTI_bool_V2DI, 0 }, - { ALTIVEC_BUILTIN_VEC_PACK, P8V_BUILTIN_VPKUDUM, + { ALTIVEC_BUILTIN_VEC_PACK, P8V_BUILTIN_FLOAT2_V2DF, RS6000_BTI_V4SF, RS6000_BTI_V2DF, RS6000_BTI_V2DF, 0 }, { P8V_BUILTIN_VEC_NEG, P8V_BUILTIN_NEG_V16QI, Index: gcc/testsuite/gcc.target/powerpc/builtins-3-p8.c =================================================================== --- gcc/testsuite/gcc.target/powerpc/builtins-3-p8.c (revision 261341) +++ gcc/testsuite/gcc.target/powerpc/builtins-3-p8.c (working copy) @@ -11,12 +11,6 @@ test_eq_long_long (vector bool long long x, vector return vec_cmpeq (x, y); } -vector float -test_pack_float (vector double x, vector double y) -{ - return vec_pack (x, y); -} - vector unsigned char test_vsi_packs_vusi_vusi (vector unsigned short x, vector unsigned short y) @@ -214,7 +208,6 @@ test_neg_double (vector double x) /* Expected test results: test_eq_long_long 1 vcmpequd inst - test_pack_float 1 vpkudum inst test_vsi_packs_vsll_vsll 1 vpksdss test_vui_packs_vull_vull 1 vpkudus test_vui_packs_vssi_vssi 1 vpkshss @@ -239,7 +232,6 @@ test_neg_double (vector double x) */ /* { dg-final { scan-assembler-times "vcmpequd" 1 } } */ -/* { dg-final { scan-assembler-times "vpkudum" 1 } } */ /* { dg-final { scan-assembler-times "vpksdss" 1 } } */ /* { dg-final { scan-assembler-times "vpkudus" 1 } } */ /* { dg-final { scan-assembler-times "vpkuhus" 2 } } */ Index: gcc/testsuite/gcc.target/powerpc/builtins-9.c =================================================================== --- gcc/testsuite/gcc.target/powerpc/builtins-9.c (nonexistent) +++ gcc/testsuite/gcc.target/powerpc/builtins-9.c (working copy) @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-require-effective-target powerpc_p8vector_ok } */ +/* Expect same instruction selecton on p8 and above. Fix if future + targets behave differently. */ +/* { dg-options "-O3 -maltivec" } */ +/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } } */ + +#include <altivec.h> + +vector float +test_pack_float (vector double x, vector double y) +{ + return vec_pack (x, y); +} + +/* { dg-final { scan-assembler-times "vmrgew" 1 { target be } } } */ +/* { dg-final { scan-assembler-times "vmrgow" 1 { target le } } } */ + +/* { dg-final { scan-assembler-times "xvcvdpsp" 2 } } */ +/* { dg-final { scan-assembler-times "xxpermdi" 2 } } */ + Index: gcc/testsuite/gcc.target/powerpc/fold-vec-pack-double.c =================================================================== --- gcc/testsuite/gcc.target/powerpc/fold-vec-pack-double.c (revision 261341) +++ gcc/testsuite/gcc.target/powerpc/fold-vec-pack-double.c (working copy) @@ -3,7 +3,10 @@ /* { dg-do compile } */ /* { dg-require-effective-target powerpc_p8vector_ok } */ -/* { dg-options "-mvsx -mpower8-vector -O2" } */ +/* Expect same instruction selecton on p8 and above. Fix if future + targets behave differently. */ +/* { dg-options "-mvsx -O2" } */ +/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } } */ #include <altivec.h> @@ -15,4 +18,5 @@ test_pack (vector double vd2, vector double vd3) return vec_pack (vd2, vd3); } -/* { dg-final { scan-assembler-times "vpkudum" 1 } } */ +/* { dg-final { scan-assembler-times "vmrgew" 1 { target be } } } */ +/* { dg-final { scan-assembler-times "vmrgow" 1 { target le } } } */