From: Jacob Lifshay <programmerjake@gmail.com>
Date: Wed, 15 Mar 2023 10:59:23 +0000 (-0700)
Subject: fix limit and move comment
X-Git-Tag: opf_rfc_ls001_v3~161
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=e42230fca8075461a638c81250e1ff5ab9dcf5fa;p=libreriscv.git

fix limit and move comment
---

diff --git a/openpower/sv/int_fp_mv.mdwn b/openpower/sv/int_fp_mv.mdwn
index a1c0981ee..ff64e6654 100644
--- a/openpower/sv/int_fp_mv.mdwn
+++ b/openpower/sv/int_fp_mv.mdwn
@@ -636,17 +636,18 @@ switch(CVM)
             result <- si64_CONVERT_FROM_BFP(range_max)
     default:  # JavaScript semantics
         # CVM = 6, 7 are illegal instructions
-        limit <- bfp_CONVERT_FROM_UI64(0xFFFF_FFFF_FFFF_FFFF)
+
+        # this works because the largest type we try to
+        # convert from has 53 significand bits, and the
+        # largest type we try to convert to has 64 bits,
+        # and the sum of those is strictly less than the
+        # 128 bits of the intermediate result.
+        limit <- bfp_CONVERT_FROM_UI128([1] * 128)
         if IsInf(rnd) or IsNaN(rnd) then
             result <- [0] * 64
         else if bfp_COMPARE_GT(bfp_ABSOLUTE(rnd), limit) then
             result <- [0] * 64
         else
-            # this works because the largest type we try to
-            # convert from has 53 significand bits, and the
-            # largest type we try to convert to has 64 bits,
-            # and the sum of those is strictly less than the
-            # 128 bits of the intermediate result.
             result128 <- si128_CONVERT_FROM_BFP(rnd)
             result <- result128[64:127] & js_mask