Hi, As mentioned in PR108338, on p9, we could use mtvsrws to implement the bitcast from SI to SF (or lowpart DI to SF).
For code: *(long long*)buff = di; float f = *(float*)(buff); "sldi 9,3,32 ; mtvsrd 1,9 ; xscvspdpn 1,1" is generated. A better one would be "mtvsrws 1,3 ; xscvspdpn 1,1". Compare with previous patch: https://gcc.gnu.org/pipermail/gcc-patches/2023-July/623533.html "highpart DI-->SF" is put to a seperate patch. Pass bootstrap and regression on ppc64{,le}. Is this ok for trunk? BR, Jeff (Jiufu Guo) gcc/ChangeLog: * config/rs6000/rs6000.md (movsf_from_si): Update to generate mtvsrws for P9. gcc/testsuite/ChangeLog: * gcc.target/powerpc/pr108338.c: Updated to check mtvsrws for p9. --- gcc/config/rs6000/rs6000.md | 25 ++++++++++++++++----- gcc/testsuite/gcc.target/powerpc/pr108338.c | 6 +++-- 2 files changed, 23 insertions(+), 8 deletions(-) diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md index 8c92cbf976de915136ad5dba24e69a363d21438d..c03e677bca79e8fb1acb276d07d0acfae009f6d8 100644 --- a/gcc/config/rs6000/rs6000.md +++ b/gcc/config/rs6000/rs6000.md @@ -8280,13 +8280,26 @@ (define_insn_and_split "movsf_from_si" { rtx op0 = operands[0]; rtx op1 = operands[1]; - rtx op2 = operands[2]; - rtx op1_di = gen_rtx_REG (DImode, REGNO (op1)); - /* Move SF value to upper 32-bits for xscvspdpn. */ - emit_insn (gen_ashldi3 (op2, op1_di, GEN_INT (32))); - emit_insn (gen_p8_mtvsrd_sf (op0, op2)); - emit_insn (gen_vsx_xscvspdpn_directmove (op0, op0)); + /* Move lowpart 32-bits from register for SFmode. */ + if (TARGET_P9_VECTOR) + { + /* Using mtvsrws;xscvspdpn. */ + rtx op0_v = gen_rtx_REG (V4SImode, REGNO (op0)); + emit_insn (gen_vsx_splat_v4si (op0_v, op1)); + emit_insn (gen_vsx_xscvspdpn_directmove (op0, op0)); + } + else + { + rtx op2 = operands[2]; + rtx op1_di = gen_rtx_REG (DImode, REGNO (op1)); + + /* Using ashl;mtvsrd;xscvspdpn. */ + emit_insn (gen_ashldi3 (op2, op1_di, GEN_INT (32))); + emit_insn (gen_p8_mtvsrd_sf (op0, op2)); + emit_insn (gen_vsx_xscvspdpn_directmove (op0, op0)); + } + DONE; } [(set_attr "length" diff --git a/gcc/testsuite/gcc.target/powerpc/pr108338.c b/gcc/testsuite/gcc.target/powerpc/pr108338.c index 6db65595343c2407fc32f68f5f52a1f7196c371d..0565e5254ed0a8cc579cf505a3f865426dcf62ae 100644 --- a/gcc/testsuite/gcc.target/powerpc/pr108338.c +++ b/gcc/testsuite/gcc.target/powerpc/pr108338.c @@ -19,9 +19,11 @@ float __attribute__ ((noipa)) sf_from_di_off4 (long long l) /* Under lp64, parameter 'l' is in one DI reg, then bitcast sub DI to SF. */ /* { dg-final { scan-assembler-times {\mxscvspdpn\M} 2 { target { lp64 && has_arch_pwr8 } } } } */ -/* { dg-final { scan-assembler-times {\mmtvsrd\M} 2 { target { lp64 && has_arch_pwr8 } } } } */ +/* { dg-final { scan-assembler-times {\mmtvsrd\M} 2 { target { lp64 && { has_arch_pwr8 && { ! has_arch_pwr9 } } } } } } */ +/* { dg-final { scan-assembler-times {\msldi\M} 1 { target { lp64 && { has_arch_pwr8 && { ! has_arch_pwr9 } } } } } } */ +/* { dg-final { scan-assembler-times {\mmtvsrd\M} 1 { target { lp64 && has_arch_pwr9 } } } } */ +/* { dg-final { scan-assembler-times {\mmtvsrws\M} 1 { target { lp64 && has_arch_pwr9 } } } } */ /* { dg-final { scan-assembler-times {\mrldicr\M} 1 { target { lp64 && has_arch_pwr8 } } } } */ -/* { dg-final { scan-assembler-times {\msldi\M} 1 { target { lp64 && has_arch_pwr8 } } } } */ union di_sf_sf { -- 2.25.1
