libmach: fix disassembly of FCMOVcc and FCOMI

The optable for 0xDB is handled specially.

This was the cause of a really weird bug
when using cov (386!) on the math package.

A real head-scratcher.

R=rsc
CC=golang-dev
https://golang.org/cl/4639066

diff --git a/src/libmach/8db.c b/src/libmach/8db.c
index 5a195baf88376e7db3db635ee880330b702b7433..5b3de69a51702f3c0cf12232f569c6df9f13e21e 100644 (file)
--- a/src/libmach/8db.c
+++ b/src/libmach/8db.c
@@ -1017,14 +1017,56 @@ static Optable optabDB[8+64] =
 [0x03] =       { 0,0,          "FMOVLP F0,%e" },
 [0x05] =       { 0,0,          "FMOVX  %e,F0" },
 [0x07] =       { 0,0,          "FMOVXP F0,%e" },
-[0x08] =       { 0,0,          "FCMOVCC        %f,F0" },
-[0x09] =       { 0,0,          "FCMOVNE        %f,F0" },
-[0x0a] =       { 0,0,          "FCMOVHI        %f,F0" },
-[0x0b] =       { 0,0,          "FCMOVNU        %f,F0" },
-[0x0d] =       { 0,0,          "FUCOMI F0,%f" },
-[0x0e] =       { 0,0,          "FCOMI  F0,%f" },
+[0x08] =       { 0,0,          "FCMOVCC        F0,F0" },       /* Mod R/M = 11xx xxxx*/
+[0x09] =       { 0,0,          "FCMOVCC        F1,F0" },
+[0x0a] =       { 0,0,          "FCMOVCC        F2,F0" },
+[0x0b] =       { 0,0,          "FCMOVCC        F3,F0" },
+[0x0c] =       { 0,0,          "FCMOVCC        F4,F0" },
+[0x0d] =       { 0,0,          "FCMOVCC        F5,F0" },
+[0x0e] =       { 0,0,          "FCMOVCC        F6,F0" },
+[0x0f] =       { 0,0,          "FCMOVCC        F7,F0" },
+[0x10] =       { 0,0,          "FCMOVNE        F0,F0" },
+[0x11] =       { 0,0,          "FCMOVNE        F1,F0" },
+[0x12] =       { 0,0,          "FCMOVNE        F2,F0" },
+[0x13] =       { 0,0,          "FCMOVNE        F3,F0" },
+[0x14] =       { 0,0,          "FCMOVNE        F4,F0" },
+[0x15] =       { 0,0,          "FCMOVNE        F5,F0" },
+[0x16] =       { 0,0,          "FCMOVNE        F6,F0" },
+[0x17] =       { 0,0,          "FCMOVNE        F7,F0" },
+[0x18] =       { 0,0,          "FCMOVHI        F0,F0" },
+[0x19] =       { 0,0,          "FCMOVHI        F1,F0" },
+[0x1a] =       { 0,0,          "FCMOVHI        F2,F0" },
+[0x1b] =       { 0,0,          "FCMOVHI        F3,F0" },
+[0x1c] =       { 0,0,          "FCMOVHI        F4,F0" },
+[0x1d] =       { 0,0,          "FCMOVHI        F5,F0" },
+[0x1e] =       { 0,0,          "FCMOVHI        F6,F0" },
+[0x1f] =       { 0,0,          "FCMOVHI        F7,F0" },
+[0x20] =       { 0,0,          "FCMOVNU        F0,F0" },
+[0x21] =       { 0,0,          "FCMOVNU        F1,F0" },
+[0x22] =       { 0,0,          "FCMOVNU        F2,F0" },
+[0x23] =       { 0,0,          "FCMOVNU        F3,F0" },
+[0x24] =       { 0,0,          "FCMOVNU        F4,F0" },
+[0x25] =       { 0,0,          "FCMOVNU        F5,F0" },
+[0x26] =       { 0,0,          "FCMOVNU        F6,F0" },
+[0x27] =       { 0,0,          "FCMOVNU        F7,F0" },
 [0x2a] =       { 0,0,          "FCLEX" },
 [0x2b] =       { 0,0,          "FINIT" },
+[0x30] =       { 0,0,          "FUCOMI F0,F0" },
+[0x31] =       { 0,0,          "FUCOMI F1,F0" },
+[0x32] =       { 0,0,          "FUCOMI F2,F0" },
+[0x33] =       { 0,0,          "FUCOMI F3,F0" },
+[0x34] =       { 0,0,          "FUCOMI F4,F0" },
+[0x35] =       { 0,0,          "FUCOMI F5,F0" },
+[0x36] =       { 0,0,          "FUCOMI F6,F0" },
+[0x37] =       { 0,0,          "FUCOMI F7,F0" },
+[0x38] =       { 0,0,          "FCOMI  F0,F0" },
+[0x39] =       { 0,0,          "FCOMI  F1,F0" },
+[0x3a] =       { 0,0,          "FCOMI  F2,F0" },
+[0x3b] =       { 0,0,          "FCOMI  F3,F0" },
+[0x3c] =       { 0,0,          "FCOMI  F4,F0" },
+[0x3d] =       { 0,0,          "FCOMI  F5,F0" },
+[0x3e] =       { 0,0,          "FCOMI  F6,F0" },
+[0x3f] =       { 0,0,          "FCOMI  F7,F0" },
 };
 
 static Optable optabDC[8+8] =