ir: barebones IR passes checked contracts

7 files changed, 26 insertions, 2 deletions

diff --git a/ir/abi0.c b/ir/abi0.c
index 895277c..fe1a7e3 100644
--- a/ir/abi0.c
+++ b/ir/abi0.c
@@ -348,6 +348,8 @@ abi0(struct function *fn)
    struct block *blk;
    union ref sret = {0};
 
+   FREQUIRE(FNUSE);
+
    if (fn->retty.t == TYVOID) {
       fn->nabiret = 0;
    } else {
@@ -435,6 +437,9 @@ abi0(struct function *fn)
       blk->id = id++;
    } while ((blk = blk->lnext) != fn->entry);
 
+   /* vaargs might break */
+   fn->prop &= ~(FNBLKID | FNRPO);
+
    if (ccopt.dbg.a) {
       bfmt(ccopt.dbgout, "<< After abi0 >>\n");
       irdump(fn);
diff --git a/ir/cfg.c b/ir/cfg.c
index e79dc63..758fa4e 100644
--- a/ir/cfg.c
+++ b/ir/cfg.c
@@ -10,6 +10,7 @@ porec(struct block ***rpo, struct block *b)
    *--*rpo = b;
 }
 
+/* also blkid */
 void
 sortrpo(struct function *fn)
 {
@@ -47,6 +48,8 @@ sortrpo(struct function *fn)
    }
    fn->entry->lprev = rpo[-1];
    rpo[-1]->lnext = fn->entry;
+
+   fn->prop |= FNBLKID | FNRPO;
 }
 
 /* vim:set ts=3 sw=3 expandtab: */
diff --git a/ir/ir.c b/ir/ir.c
index 6a40991..30da628 100644
--- a/ir/ir.c
+++ b/ir/ir.c
@@ -68,6 +68,7 @@ irinit(struct function *fn)
    fn->entry = fn->curblk = allocz(fn->arena, sizeof(struct block), 0);
    fn->nblk = 1;
    fn->entry->lprev = fn->entry->lnext = fn->entry;
+   fn->prop = FNUSE; /* builder keeps this */
 }
 
 static int
@@ -552,6 +553,8 @@ fillblkids(struct function *fn)
    int i = 0;
    struct block *blk = fn->entry;
    do blk->id = i++; while ((blk = blk->lnext) != fn->entry);
+
+   fn->prop |= FNBLKID;
 }
 
 /** Misc **/
diff --git a/ir/ir.h b/ir/ir.h
index 0879b86..1c7c02e 100644
--- a/ir/ir.h
+++ b/ir/ir.h
@@ -153,6 +153,12 @@ rsiter(int *i, uvlong rs)
    return 1;
 }
 
+enum {
+   FNBLKID = 1<<0,
+   FNUSE   = 1<<1,
+   FNRPO   = 1<<2,
+   FNDOM   = 1<<3,
+};
 struct function {
    struct arena **arena;
    const char *name;
@@ -161,6 +167,7 @@ struct function {
    short *nuse;
    union type fnty, retty;
    struct abiarg *abiarg, abiret[2];
+   uint prop;
    uint nblk;
    int stksiz;
    ushort nabiarg, nabiret;
@@ -168,6 +175,7 @@ struct function {
    bool isleaf;
    regset regusage;
 };
+#define FREQUIRE(_prop) assert((fn->prop & (_prop)) && "preconditions not met")
 
 enum objkind { OBJELF };
 enum mcisa { ISamd64 };
diff --git a/ir/optmem.c b/ir/optmem.c
index d28ea53..3f5852b 100644
--- a/ir/optmem.c
+++ b/ir/optmem.c
@@ -225,7 +225,6 @@ cmpuse(const void *a, const void *b)
    return blkfindins(blk, ua->u) - blkfindins(blk, ub->u);
 }
 
-/* require use, blkid; keeps use */
 void
 mem2reg(struct function *fn)
 {
@@ -233,6 +232,8 @@ mem2reg(struct function *fn)
    struct ssabuilder sb = { .nblk = fn->nblk };
    struct block *blk;
 
+   FREQUIRE(FNUSE);
+
    if (fn->nblk <= 64 * arraylength(bsbuf[0])) {
       sb.sealed = bsbuf[0];
       sb.marked = bsbuf[1];
diff --git a/ir/regalloc.c b/ir/regalloc.c
index 8c8b39c..e9909ae 100644
--- a/ir/regalloc.c
+++ b/ir/regalloc.c
@@ -411,6 +411,8 @@ fixcssa(struct function *fn)
          }
       }
    } while ((blk = blk->lnext) != fn->entry);
+
+   fn->prop &= ~FNBLKID;
 }
 
 static inline bool
diff --git a/ir/ssa.c b/ir/ssa.c
index 5a3db2f..f6c9d6f 100644
--- a/ir/ssa.c
+++ b/ir/ssa.c
@@ -1,11 +1,11 @@
 #include "ir.h"
 
-/* require use, keeps use */
 void
 copyopt(struct function *fn)
 {
    struct block *blk = fn->entry;
 
+   FREQUIRE(FNUSE);
    do {
       for (int i = 0; i < blk->ins.n; ++i) {
          union ref var = mkref(RTMP, blk->ins.p[i]);
@@ -53,6 +53,8 @@ filluses(struct function *fn)
       adduse(blk, USERJUMP, blk->jmp.arg[0]);
       adduse(blk, USERJUMP, blk->jmp.arg[1]);
    } while ((blk = blk->lnext) != fn->entry);
+
+   fn->prop |= FNUSE;
 }
 
 /* vim:set ts=3 sw=3 expandtab: */