coverage tweaks

* handle new 6g shift sequence
* assume 6.out

R=r
DELTA=24  (20 added, 0 deleted, 4 changed)
OCL=19593
CL=19596

diff --git a/src/cmd/cov/main.c b/src/cmd/cov/main.c
index dbd9d0daec2e77e6c03ecf769490c0fc06b8daca..4856adf493d75c98b8516551704862b70d846407 100644 (file)
--- a/src/cmd/cov/main.c
+++ b/src/cmd/cov/main.c
@@ -21,7 +21,7 @@ typedef struct Ureg Ureg;
 void
 usage(void)
 {
-       fprint(2, "usage: cov 6.out [-lv] [-g regexp] [args...]\n");
+       fprint(2, "usage: cov [-lv] [-g regexp] [6.out args...]\n");
        fprint(2, "-g specifies pattern of interesting functions or files\n");
        exits("usage");
 }
@@ -162,7 +162,7 @@ missing(uvlong pc, uvlong epc)
 
        if(epc - pc == 2 || epc -pc == 3) {
                // check for XORL inside shift.
-               // (on x86 have to implement large shift with explicit zeroing).
+               // (on x86 have to implement large left or unsigned right shift with explicit zeroing).
                //      f+90 0x00002c9f CMPL    CX,$20
                //      f+93 0x00002ca2 JCS     f+97(SB)
                //      f+95 0x00002ca4 XORL    AX,AX <<<
@@ -183,6 +183,24 @@ missing(uvlong pc, uvlong epc)
                }
        }
 
+       if(epc - pc == 3) {
+               // check for SAR inside shift.
+               // (on x86 have to implement large signed right shift as >>31).
+               //      f+36 0x00016216 CMPL    CX,$20
+               //      f+39 0x00016219 JCS     f+3e(SB)
+               //      f+3b 0x0001621b SARL    $1f,AX <<<
+               //      f+3e 0x0001621e SARL    CL,AX
+               //      f+40 0x00016220 XORL    CX,CX
+               //      f+42 0x00016222 CMPL    CX,AX
+               buf[0] = 0;
+               machdata->das(text, pc, 0, buf, sizeof buf);
+               if(strncmp(buf, "SAR", 3) == 0) {
+                       machdata->das(text, epc, 0, buf, sizeof buf);
+                       if(strncmp(buf, "SAR", 3) == 0)
+                               return;
+               }
+       }
+
        // show first instruction to make clear where we were.
        machdata->das(text, pc, 0, buf, sizeof buf);
 
@@ -379,8 +397,10 @@ main(int argc, char **argv)
        getwd(cwd, sizeof cwd);
        ncwd = strlen(cwd);
 
-       if(argc < 1)
-               usage();
+       if(argc == 0) {
+               *--argv = "6.out";
+               argc++;
+       }
        fd = open(argv[0], OREAD);
        if(fd < 0)
                sysfatal("open %s: %r", argv[0]);