diff options
Diffstat (limited to 'src/cmd/5g/opt.h')
| -rw-r--r-- | src/cmd/5g/opt.h | 44 |
1 files changed, 30 insertions, 14 deletions
diff --git a/src/cmd/5g/opt.h b/src/cmd/5g/opt.h index 1946c1d33..a606f1d31 100644 --- a/src/cmd/5g/opt.h +++ b/src/cmd/5g/opt.h @@ -63,8 +63,8 @@ enum uint32 BLOAD(Reg*); uint32 BSTORE(Reg*); -uint32 LOAD(Reg*); -uint32 STORE(Reg*); +uint64 LOAD(Reg*); +uint64 STORE(Reg*); */ // A Reg is a wrapper around a single Prog (one instruction) that holds @@ -75,12 +75,18 @@ struct Reg { Flow f; - Bits set; // variables written by this instruction. - Bits use1; // variables read by prog->from. - Bits use2; // variables read by prog->to. + Bits set; // regopt variables written by this instruction. + Bits use1; // regopt variables read by prog->from. + Bits use2; // regopt variables read by prog->to. + // refahead/refbehind are the regopt variables whose current + // value may be used in the following/preceding instructions + // up to a CALL (or the value is clobbered). Bits refbehind; Bits refahead; + // calahead/calbehind are similar, but for variables in + // instructions that are reachable after hitting at least one + // CALL. Bits calbehind; Bits calahead; Bits regdiff; @@ -93,6 +99,16 @@ struct Reg #define NRGN 600 /*c2go enum { NRGN = 600 }; */ + +// A Rgn represents a single regopt variable over a region of code +// where a register could potentially be dedicated to that variable. +// The code encompassed by a Rgn is defined by the flow graph, +// starting at enter, flood-filling forward while varno is refahead +// and backward while varno is refbehind, and following branches. A +// single variable may be represented by multiple disjoint Rgns and +// each Rgn may choose a different register for that variable. +// Registers are allocated to regions greedily in order of descending +// cost. struct Rgn { Reg* enter; @@ -144,8 +160,8 @@ void prop(Reg*, Bits, Bits); void synch(Reg*, Bits); uint32 allreg(uint32, Rgn*); void paint1(Reg*, int); -uint32 paint2(Reg*, int); -void paint3(Reg*, int, int32, int); +uint32 paint2(Reg*, int, int); +void paint3(Reg*, int, uint32, int); void addreg(Adr*, int); void dumpit(char *str, Flow *r0, int); @@ -156,10 +172,10 @@ void peep(Prog*); void excise(Flow*); int copyu(Prog*, Adr*, Adr*); -int32 RtoB(int); -int32 FtoB(int); -int BtoR(int32); -int BtoF(int32); +uint32 RtoB(int); +uint32 FtoB(int); +int BtoR(uint32); +int BtoF(uint32); /* * prog.c @@ -187,16 +203,16 @@ enum SizeF = 1<<7, // float aka float32 SizeD = 1<<8, // double aka float64 - // Left side: address taken, read, write. + // Left side (Prog.from): address taken, read, write. LeftAddr = 1<<9, LeftRead = 1<<10, LeftWrite = 1<<11, - // Register in middle; never written. + // Register in middle (Prog.reg); only ever read. RegRead = 1<<12, CanRegRead = 1<<13, - // Right side: address taken, read, write. + // Right side (Prog.to): address taken, read, write. RightAddr = 1<<14, RightRead = 1<<15, RightWrite = 1<<16, |