Off list, Segher asked that I break the patch eliminating a shift right when transfering SFmode from a vector register to a GPR register down into smaller chunks. The power7 and power8 instructions that convert values in the double precision format to single precision actually duplicate the 32-bits in the first word and second word (the ISA says the second word is undefined). We are in the process of issuing an update to ISA 3.0 to clarify that this will be the required behavior going forward.
I have broken the patches down to 8 chunks. Some of the patch are just cosmetic of things I noticed while doing the main patch. One patch eliminates the shift. Another fixes up the peephole2 that optimizes putting a SFmode into a union and then doing masking on the value. And the final patch updates the tests that need to be changed. I have verified that each of these sub-patches build, and after all 8 patches have been applied, I did the full bootstrap and regresion test, and like the previous combination patch there were no regressions. If only some of the patches are applied, then there will be 3 regressions until the remaining patches are applied. This is patch #2. Can I check this into the trunk? Compared to the previous patch, I simplified this to use zero_extendsidi2 instead of using an UNSPEC, and I deleted the UNSPEC. 2017-09-25 Michael Meissner <meiss...@linux.vnet.ibm.com> * config/rs6000/rs6000.md (movsi_from_sf): Adjust code to eliminate doing a 32-bit shift right or vector extract after doing XSCVDPSPN. Use zero_extendsidi2 instead of p8_mfvsrd_4_disf to move the value to the GPRs. (movdi_from_sf_zero_ext): Likewise. (reload_gpr_from_vsxsf): Likewise. (p8_mfvsrd_4_disf): Delete, no longer used. -- 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/rs6000.md =================================================================== --- gcc/config/rs6000/rs6000.md (revision 253169) +++ gcc/config/rs6000/rs6000.md (working copy) @@ -6806,25 +6806,25 @@ (define_insn "*movsi_internal1_single" ;; needed. ;; MR LWZ LFIWZX LXSIWZX STW -;; STFS STXSSP STXSSPX VSX->GPR MTVSRWZ -;; VSX->VSX +;; STFS STXSSP STXSSPX VSX->GPR VSX->VSX, +;; MTVSRWZ (define_insn_and_split "movsi_from_sf" [(set (match_operand:SI 0 "nonimmediate_operand" "=r, r, ?*wI, ?*wH, m, - m, wY, Z, r, wIwH, - ?wK") + m, wY, Z, r, ?*wIwH, + wIwH") (unspec:SI [(match_operand:SF 1 "input_operand" "r, m, Z, Z, r, - f, wb, wu, wIwH, r, - wK")] + f, wb, wu, wIwH, wIwH, + r")] UNSPEC_SI_FROM_SF)) (clobber (match_scratch:V4SF 2 "=X, X, X, X, X, - X, X, X, wa, X, - wa"))] + X, X, X, wIwH, X, + X"))] "TARGET_NO_SF_SUBREG && (register_operand (operands[0], SImode) @@ -6839,10 +6839,10 @@ (define_insn_and_split "movsi_from_sf" stxssp %1,%0 stxsspx %x1,%y0 # - mtvsrwz %x0,%1 - #" + xscvdpspn %x0,%x1 + mtvsrwz %x0,%1" "&& reload_completed - && register_operand (operands[0], SImode) + && int_reg_operand (operands[0], SImode) && vsx_reg_sfsubreg_ok (operands[1], SFmode)" [(const_int 0)] { @@ -6850,52 +6850,41 @@ (define_insn_and_split "movsi_from_sf" rtx op1 = operands[1]; rtx op2 = operands[2]; rtx op0_di = gen_rtx_REG (DImode, REGNO (op0)); + rtx op2_si = gen_rtx_REG (SImode, REGNO (op2)); emit_insn (gen_vsx_xscvdpspn_scalar (op2, op1)); - - if (int_reg_operand (op0, SImode)) - { - emit_insn (gen_p8_mfvsrd_4_disf (op0_di, op2)); - emit_insn (gen_lshrdi3 (op0_di, op0_di, GEN_INT (32))); - } - else - { - rtx op1_v16qi = gen_rtx_REG (V16QImode, REGNO (op1)); - rtx byte_off = VECTOR_ELT_ORDER_BIG ? const0_rtx : GEN_INT (12); - emit_insn (gen_vextract4b (op0_di, op1_v16qi, byte_off)); - } - + emit_insn (gen_zero_extendsidi2 (op0_di, op2_si)); DONE; } [(set_attr "type" "*, load, fpload, fpload, store, - fpstore, fpstore, fpstore, mftgpr, mffgpr, - veclogical") + fpstore, fpstore, fpstore, mftgpr, fp, + mffgpr") (set_attr "length" "4, 4, 4, 4, 4, - 4, 4, 4, 12, 4, - 8")]) + 4, 4, 4, 8, 4, + 4")]) ;; movsi_from_sf with zero extension ;; ;; RLDICL LWZ LFIWZX LXSIWZX VSX->GPR -;; MTVSRWZ VSX->VSX +;; VSX->VSX MTVSRWZ (define_insn_and_split "*movdi_from_sf_zero_ext" [(set (match_operand:DI 0 "gpc_reg_operand" "=r, r, ?*wI, ?*wH, r, - wIwH, ?wK") + wK, wIwH") (zero_extend:DI (unspec:SI [(match_operand:SF 1 "input_operand" "r, m, Z, Z, wIwH, - r, wK")] + wIwH, r")] UNSPEC_SI_FROM_SF))) (clobber (match_scratch:V4SF 2 "=X, X, X, X, wa, - X, wa"))] + wIwH, X"))] "TARGET_DIRECT_MOVE_64BIT && (register_operand (operands[0], DImode) @@ -6906,40 +6895,29 @@ (define_insn_and_split "*movdi_from_sf_z lfiwzx %0,%y1 lxsiwzx %x0,%y1 # - mtvsrwz %x0,%1 - #" + # + mtvsrwz %x0,%1" "&& reload_completed + && register_operand (operands[0], DImode) && vsx_reg_sfsubreg_ok (operands[1], SFmode)" [(const_int 0)] { rtx op0 = operands[0]; rtx op1 = operands[1]; rtx op2 = operands[2]; + rtx op2_si = gen_rtx_REG (SImode, reg_or_subregno (op2)); emit_insn (gen_vsx_xscvdpspn_scalar (op2, op1)); - - if (int_reg_operand (op0, DImode)) - { - emit_insn (gen_p8_mfvsrd_4_disf (op0, op2)); - emit_insn (gen_lshrdi3 (op0, op0, GEN_INT (32))); - } - else - { - rtx op0_si = gen_rtx_REG (SImode, REGNO (op0)); - rtx op1_v16qi = gen_rtx_REG (V16QImode, REGNO (op1)); - rtx byte_off = VECTOR_ELT_ORDER_BIG ? const0_rtx : GEN_INT (12); - emit_insn (gen_vextract4b (op0_si, op1_v16qi, byte_off)); - } - + emit_insn (gen_zero_extendsidi2 (op0, op2_si)); DONE; } [(set_attr "type" "*, load, fpload, fpload, mftgpr, - mffgpr, veclogical") + vecexts, mffgpr") (set_attr "length" - "4, 4, 4, 4, 12, - 4, 8")]) + "4, 4, 4, 4, 8, + 8, 4")]) ;; Split a load of a large constant into the appropriate two-insn ;; sequence. @@ -8439,9 +8417,9 @@ (define_insn_and_split "reload_gpr_from_ (define_insn_and_split "reload_gpr_from_vsxsf" [(set (match_operand:SF 0 "register_operand" "=r") - (unspec:SF [(match_operand:SF 1 "register_operand" "wa")] + (unspec:SF [(match_operand:SF 1 "register_operand" "ww")] UNSPEC_P8V_RELOAD_FROM_VSX)) - (clobber (match_operand:V4SF 2 "register_operand" "=wa"))] + (clobber (match_operand:V4SF 2 "register_operand" "=wIwH"))] "TARGET_POWERPC64 && TARGET_DIRECT_MOVE" "#" "&& reload_completed" @@ -8450,23 +8428,15 @@ (define_insn_and_split "reload_gpr_from_ rtx op0 = operands[0]; rtx op1 = operands[1]; rtx op2 = operands[2]; - rtx diop0 = simplify_gen_subreg (DImode, op0, SFmode, 0); + rtx op0_di = gen_rtx_REG (DImode, reg_or_subregno (op0)); + rtx op2_si = gen_rtx_REG (SImode, reg_or_subregno (op2)); emit_insn (gen_vsx_xscvdpspn_scalar (op2, op1)); - emit_insn (gen_p8_mfvsrd_4_disf (diop0, op2)); - emit_insn (gen_lshrdi3 (diop0, diop0, GEN_INT (32))); + emit_insn (gen_zero_extendsidi2 (op0_di, op2_si)); DONE; } - [(set_attr "length" "12") - (set_attr "type" "three")]) - -(define_insn "p8_mfvsrd_4_disf" - [(set (match_operand:DI 0 "register_operand" "=r") - (unspec:DI [(match_operand:V4SF 1 "register_operand" "wa")] - UNSPEC_P8V_RELOAD_FROM_VSX))] - "TARGET_POWERPC64 && TARGET_DIRECT_MOVE" - "mfvsrd %0,%x1" - [(set_attr "type" "mftgpr")]) + [(set_attr "length" "8") + (set_attr "type" "two")]) ;; Next come the multi-word integer load and store and the load and store