Re: [PATCH v2 1/9] aarch64: Accept 0 as first argument to compares
On 3/31/20 9:55 AM, Richard Sandiford wrote: >> (define_insn "cmp" >>[(set (reg:CC CC_REGNUM) >> -(compare:CC (match_operand:GPI 0 "register_operand" "rk,rk,rk") >> -(match_operand:GPI 1 "aarch64_plus_operand" "r,I,J")))] >> +(compare:CC (match_operand:GPI 0 "aarch64_reg_or_zero" "rk,rk,rkZ") >> +(match_operand:GPI 1 "aarch64_plus_operand" "I,J,rZ")))] >>"" >>"@ >> - cmp\\t%0, %1 >> cmp\\t%0, %1 >> - cmn\\t%0, #%n1" >> - [(set_attr "type" "alus_sreg,alus_imm,alus_imm")] >> + cmn\\t%0, #%n1 >> + cmp\\t%0, %1" >> + [(set_attr "type" "alus_imm,alus_imm,alus_sreg")] >> ) >> >> (define_insn "fcmp" > > ...does adding 'Z' to operand 1 enable any new combinations? Not useful ones, on reflection, but given it's a valid combination, it's easier to include it than not. I can certainly remove that. r~
Re: [PATCH v2 1/9] aarch64: Accept 0 as first argument to compares
Richard Henderson writes: > While cmp (extended register) and cmp (immediate) uses , > cmp (shifted register) uses . So we can perform cmp xzr, x0. > > For ccmp, we only have as an input. > > * config/aarch64/aarch64.md (cmp): For operand 0, use > aarch64_reg_or_zero. Shuffle reg/reg to last alternative > and accept Z. > (@ccmpcc): For operand 0, use aarch64_reg_or_zero and Z. > (@ccmpcc_rev): Likewise. Looks good, but... > --- > gcc/config/aarch64/aarch64.md | 14 +++--- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md > index c7c4d1dd519..b9ae51e48dd 100644 > --- a/gcc/config/aarch64/aarch64.md > +++ b/gcc/config/aarch64/aarch64.md > @@ -502,7 +502,7 @@ > [(match_operand 0 "cc_register" "") > (const_int 0)]) > (compare:CC_ONLY > - (match_operand:GPI 2 "register_operand" "r,r,r") > + (match_operand:GPI 2 "aarch64_reg_or_zero" "rZ,rZ,rZ") > (match_operand:GPI 3 "aarch64_ccmp_operand" "r,Uss,Usn")) > (unspec:CC_ONLY > [(match_operand 5 "immediate_operand")] > @@ -542,7 +542,7 @@ > [(match_operand 5 "immediate_operand")] > UNSPEC_NZCV) > (compare:CC_ONLY > - (match_operand:GPI 2 "register_operand" "r,r,r") > + (match_operand:GPI 2 "aarch64_reg_or_zero" "rZ,rZ,rZ") > (match_operand:GPI 3 "aarch64_ccmp_operand" "r,Uss,Usn"] >"" >"@ > @@ -3961,14 +3961,14 @@ > > (define_insn "cmp" >[(set (reg:CC CC_REGNUM) > - (compare:CC (match_operand:GPI 0 "register_operand" "rk,rk,rk") > - (match_operand:GPI 1 "aarch64_plus_operand" "r,I,J")))] > + (compare:CC (match_operand:GPI 0 "aarch64_reg_or_zero" "rk,rk,rkZ") > + (match_operand:GPI 1 "aarch64_plus_operand" "I,J,rZ")))] >"" >"@ > - cmp\\t%0, %1 > cmp\\t%0, %1 > - cmn\\t%0, #%n1" > - [(set_attr "type" "alus_sreg,alus_imm,alus_imm")] > + cmn\\t%0, #%n1 > + cmp\\t%0, %1" > + [(set_attr "type" "alus_imm,alus_imm,alus_sreg")] > ) > > (define_insn "fcmp" ...does adding 'Z' to operand 1 enable any new combinations? I guess it allows (compare:CC (const_int 0) (const_int 0)), but it's borderline whether that should be valid rtl. Richard
[PATCH v2 1/9] aarch64: Accept 0 as first argument to compares
While cmp (extended register) and cmp (immediate) uses , cmp (shifted register) uses . So we can perform cmp xzr, x0. For ccmp, we only have as an input. * config/aarch64/aarch64.md (cmp): For operand 0, use aarch64_reg_or_zero. Shuffle reg/reg to last alternative and accept Z. (@ccmpcc): For operand 0, use aarch64_reg_or_zero and Z. (@ccmpcc_rev): Likewise. --- gcc/config/aarch64/aarch64.md | 14 +++--- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md index c7c4d1dd519..b9ae51e48dd 100644 --- a/gcc/config/aarch64/aarch64.md +++ b/gcc/config/aarch64/aarch64.md @@ -502,7 +502,7 @@ [(match_operand 0 "cc_register" "") (const_int 0)]) (compare:CC_ONLY - (match_operand:GPI 2 "register_operand" "r,r,r") + (match_operand:GPI 2 "aarch64_reg_or_zero" "rZ,rZ,rZ") (match_operand:GPI 3 "aarch64_ccmp_operand" "r,Uss,Usn")) (unspec:CC_ONLY [(match_operand 5 "immediate_operand")] @@ -542,7 +542,7 @@ [(match_operand 5 "immediate_operand")] UNSPEC_NZCV) (compare:CC_ONLY - (match_operand:GPI 2 "register_operand" "r,r,r") + (match_operand:GPI 2 "aarch64_reg_or_zero" "rZ,rZ,rZ") (match_operand:GPI 3 "aarch64_ccmp_operand" "r,Uss,Usn"] "" "@ @@ -3961,14 +3961,14 @@ (define_insn "cmp" [(set (reg:CC CC_REGNUM) - (compare:CC (match_operand:GPI 0 "register_operand" "rk,rk,rk") - (match_operand:GPI 1 "aarch64_plus_operand" "r,I,J")))] + (compare:CC (match_operand:GPI 0 "aarch64_reg_or_zero" "rk,rk,rkZ") + (match_operand:GPI 1 "aarch64_plus_operand" "I,J,rZ")))] "" "@ - cmp\\t%0, %1 cmp\\t%0, %1 - cmn\\t%0, #%n1" - [(set_attr "type" "alus_sreg,alus_imm,alus_imm")] + cmn\\t%0, #%n1 + cmp\\t%0, %1" + [(set_attr "type" "alus_imm,alus_imm,alus_sreg")] ) (define_insn "fcmp" -- 2.20.1
