From b62f93d2b3f74922e7fd27cb39a092f81e6785d4 Mon Sep 17 00:00:00 2001
From: Bhargav Kulkarni <bhargav.kulkarni1@gmail.com>
Date: Sun, 22 Sep 2024 16:13:03 -0600
Subject: [PATCH] fix addition

---
 src/core/explain.rkt  | 11 ++++++++---
 src/core/logspace.rkt | 15 +++++++++++++--
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/core/explain.rkt b/src/core/explain.rkt
index 7be9a39cc..948d63855 100644
--- a/src/core/explain.rkt
+++ b/src/core/explain.rkt
@@ -20,6 +20,9 @@
 (provide explain
          actual-errors)
 
+(define 100.l (flonum->logfl 100.0))
+(define 32.l (flonum->logfl 32.0))
+
 (define *top-3* (make-parameter #f))
 
 (define MAX-EXP 1023)
@@ -165,6 +168,8 @@
 
          (define cond-x (abs (/ xfl (+ xfl yfl))))
          (define cond-y (abs (/ yfl (+ xfl yfl))))
+         ;(define cond-x.l (logabs (log/ xlog (log+ xlog ylog))))
+         ;(define cond-y.l (logabs (log/ ylog (log+ xlog ylog))))
 
          (define x.eps (+ 127 (bigfloat-exponent (exacts-ref x-ex))))
          (define y.eps (+ 127 (bigfloat-exponent (exacts-ref y-ex))))
@@ -546,13 +551,13 @@
   (define explanations-table
     (for/list ([(key val) (in-dict expls->points)]
                #:unless (zero? (length val)))
-      (define expr (car key))
+      (define subexpr (car key))
       (define expl (cdr key))
       (define err-count (length val))
       (define maybe-count (length (hash-ref maybe-expls->points key '())))
-      (define flow-list (make-flow-table oflow-hash uflow-hash expr expl))
+      (define flow-list (make-flow-table oflow-hash uflow-hash subexpr expl))
 
-      (list (~a (car expr)) (~a expr) (~a expl) err-count maybe-count flow-list)))
+      (list (~a (car subexpr)) (~a subexpr) (~a expl) err-count maybe-count flow-list)))
 
   (define sorted-explanations-table (take-top-n (sort explanations-table > #:key fourth)))
 
diff --git a/src/core/logspace.rkt b/src/core/logspace.rkt
index 37dc0d30c..f6d6807ee 100644
--- a/src/core/logspace.rkt
+++ b/src/core/logspace.rkt
@@ -89,8 +89,8 @@
   (if (log<= A B) A B))
 
 (define (log+ A B)
-  (define P (logmax A B))
-  (define Q (logmin A B))
+  (define P (if (log>= (logabs A) (logabs B)) A B))
+  (define Q (if (log< (logabs A) (logabs B)) A B))
   (match-define (logfl a sa ea) P)
   (match-define (logfl b sb eb) Q)
   (define x (- eb ea))
@@ -251,3 +251,14 @@
     [(list (or 'PI.f64 'PI.f32 'E.f64 'E.f32)) (flonum->logfl ((impl-info (first expr) 'fl)))]
     [(list op args ...) (cons (op->logop op) (map expr->logfl args))]
     [sym sym]))
+
+(define x (flonum->logfl 2e+103))
+(define 1.l (flonum->logfl 1.0))
+(define 2.l (flonum->logfl 2.0))
+
+(define x+1 (log+ x 1.l))
+(define 1/x+1 (log/ 1.l x+1))
+
+(define 2/x (log/ 2.l x))
+
+(define res (log- 1/x+1 2/x))