From f105ca1fc2c882c6fc1ff486a90b00a72e6532f4 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sun, 15 Sep 2002 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2002-09-15

---
 pc/main.c | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/pc/main.c b/pc/main.c
index 874ed425d2ebd333e0451a4b75a1b31c56091bf9..821bc870dc9decf037806bc54f406e4f2335e00a 100644
--- a/pc/main.c
+++ b/pc/main.c
@@ -423,14 +423,12 @@ confinit(void)
 
 static char* mathmsg[] =
 {
-	"invalid",
-	"denormalized",
-	"div-by-zero",
-	"overflow",
-	"underflow",
-	"precision",
-	"stack",
-	"error",
+	nil,	/* handled below */
+	"denormalized operand",
+	"division by zero",
+	"numeric overflow",
+	"numeric underflow",
+	"precision loss",
 };
 
 static void
@@ -446,14 +444,23 @@ mathnote(void)
 	 * Some attention should probably be paid here to the
 	 * exception masks and error summary.
 	 */
-	msg = "unknown";
-	for(i = 0; i < 8; i++){
+	msg = "unknown exception";
+	for(i = 1; i <= 5; i++){
 		if(!((1<<i) & status))
 			continue;
 		msg = mathmsg[i];
 		break;
 	}
-	sprint(note, "sys: fp: %s fppc=0x%lux", msg, up->fpsave.pc);
+	if(status & 0x01){
+		if(status & 0x30){
+			if(status & 0x200)
+				msg = "stack overflow";
+			else
+				msg = "stack underflow";
+		}else
+			msg = "invalid operation";
+	}
+	sprint(note, "sys: fp: %s fppc=0x%lux status=0x%lux", msg, up->fpsave.pc, status);
 	postnote(up, 1, note, NDebug);
 }