diff options
| -rw-r--r-- | main.c | 18 | ||||
| -rw-r--r-- | nanosec.c | 109 |
2 files changed, 117 insertions, 10 deletions
@@ -207,14 +207,14 @@ filltriangle(Memimage *dst, Point p0, Point p1, Point p2, Memimage *src) } void -shade(Memimage *dst, Memimage *(*shader)(Point)) +shade(Memimage *dst, Rectangle r, Memimage *(*shader)(Point)) { Point p; Memimage *c; - p = ZP; - for(; p.y < Dy(dst->r); p.y++) - for(p.x = 0; p.x < Dx(dst->r); p.x++) + p = r.min; + for(; p.y < r.max.y; p.y++) + for(p.x = 0; p.x < r.max.x; p.x++) if((c = shader(p)) != nil) pixel(dst, p, c); } @@ -231,10 +231,8 @@ triangleshader(Point p) t.p2 = Pt2(240,40,1); bbox = Rect( - min(min(t.p0.x, t.p1.x), t.p2.x), - min(min(t.p0.y, t.p1.y), t.p2.y), - max(max(t.p0.x, t.p1.x), t.p2.x), - max(max(t.p0.y, t.p1.y), t.p2.y) + min(min(t.p0.x, t.p1.x), t.p2.x), min(min(t.p0.y, t.p1.y), t.p2.y), + max(max(t.p0.x, t.p1.x), t.p2.x), max(max(t.p0.y, t.p1.y), t.p2.y) ); if(!ptinrect(p, bbox)) return nil; @@ -250,7 +248,7 @@ redraw(void) { lockdisplay(display); draw(screen, screen->r, display->black, nil, ZP); - loadimage(screen, screen->r, byteaddr(fb, fb->r.min), bytesperline(fb->r, fb->depth)*Dy(fb->r)); + loadimage(screen, fb->r, byteaddr(fb, fb->r.min), bytesperline(fb->r, fb->depth)*Dy(fb->r)); flushimage(display, 1); unlockdisplay(display); } @@ -334,7 +332,7 @@ threadmain(int argc, char *argv[]) triangle(fb, Pt(400,230), Pt(450,180), Pt(150, 320), red); t0 = nanosec(); - shade(fb, triangleshader); + shade(fb, rectsubpt(fb->r, fb->r.min), triangleshader); t1 = nanosec(); fprint(2, "shader took %lludns\n", t1-t0); diff --git a/nanosec.c b/nanosec.c new file mode 100644 index 0000000..f82d47a --- /dev/null +++ b/nanosec.c @@ -0,0 +1,109 @@ +#include <u.h> +#include <libc.h> +#include <tos.h> + +/* + * This code is a mixture of cpuid(1) and the nanosec() found in vmx, + * in order to force the use of nsec(2) in case we are running in a + * virtualized environment where the clock is mis-bhyve-ing. + */ + +typedef struct Res { + ulong ax, bx, cx, dx; +} Res; + +static uchar _cpuid[] = { + 0x5E, /* POP SI (PC) */ + 0x5D, /* POP BP (Res&) */ + 0x58, /* POP AX */ + 0x59, /* POP CX */ + + 0x51, /* PUSH CX */ + 0x50, /* PUSH AX */ + 0x55, /* PUSH BP */ + 0x56, /* PUSH SI */ + + 0x31, 0xDB, /* XOR BX, BX */ + 0x31, 0xD2, /* XOR DX, DX */ + + 0x0F, 0xA2, /* CPUID */ + + 0x89, 0x45, 0x00, /* MOV AX, 0(BP) */ + 0x89, 0x5d, 0x04, /* MOV BX, 4(BP) */ + 0x89, 0x4d, 0x08, /* MOV CX, 8(BP) */ + 0x89, 0x55, 0x0C, /* MOV DX, 12(BP) */ + 0xC3, /* RET */ +}; + +static Res (*cpuid)(ulong ax, ulong cx) = (Res(*)(ulong, ulong)) _cpuid; + +/* + * nsec() is wallclock and can be adjusted by timesync + * so need to use cycles() instead, but fall back to + * nsec() in case we can't + */ +uvlong +nanosec(void) +{ + static uvlong fasthz, xstart; + char buf[13], path[128]; + ulong w; + uvlong x, div; + int fd; + Res r; + + if(fasthz == ~0ULL) + return nsec() - xstart; + + if(fasthz == 0){ + /* first long in a.out header */ + snprint(path, sizeof path, "/proc/%d/text", getpid()); + fd = open(path, OREAD); + if(fd < 0) + goto Wallclock; + if(read(fd, buf, 4) != 4){ + close(fd); + goto Wallclock; + } + close(fd); + + w = ((ulong *) buf)[0]; + + switch(w){ + default: + goto Wallclock; + case 0x978a0000: /* amd64 */ + /* patch out POP BP -> POP AX */ + _cpuid[1] = 0x58; + case 0xeb010000: /* 386 */ + break; + } + segflush(_cpuid, sizeof(_cpuid)); + + r = cpuid(0x40000000, 0); + ((ulong *) buf)[0] = r.bx; + ((ulong *) buf)[1] = r.cx; + ((ulong *) buf)[2] = r.dx; + buf[12] = 0; + + if(strstr(buf, "bhyve") != nil) + goto Wallclock; + + if(_tos->cyclefreq){ + fasthz = _tos->cyclefreq; + cycles(&xstart); + } else { +Wallclock: + fasthz = ~0ULL; + xstart = nsec(); + } + return 0; + } + cycles(&x); + x -= xstart; + + /* this is ugly */ + for(div = 1000000000ULL; x < 0x1999999999999999ULL && div > 1 ; div /= 10ULL, x *= 10ULL); + + return x / (fasthz / div); +} |