[hackers] [libzahl] Add a comment about storing the carry flag || Mattias Andrée

[git]

commit 6b97020bdbdc5eb08aaa638d0649013ce9c65188
Author:     Mattias Andrée <maand...@kth.se>
AuthorDate: Fri Jun 10 13:35:41 2016 +0200
Commit:     Mattias Andrée <maand...@kth.se>
CommitDate: Fri Jun 10 13:35:41 2016 +0200

    Add a comment about storing the carry flag
    
    Signed-off-by: Mattias Andrée <maand...@kth.se>

diff --git a/src/zadd.c b/src/zadd.c
index 56c901b..179a159 100644
--- a/src/zadd.c
+++ b/src/zadd.c
@@ -25,6 +25,11 @@
        "\n    jc 1f"           \
        "\n    movq $0, %[x]"   \
        "\n 1:"
+/*
+ * I have already tried setc, cmovnc, cmovc, and adc,
+ * instead of the last four lines. There does not seem
+ * to be any better why to store the carry flag.
+ */
 
 # define ASM_ADD(N)                                                            
              \
        do {                                                                    
             \