From: drh <>
Date: Sat, 7 Dec 2024 20:01:08 +0000 (+0000)
Subject: Yet another iteration of the solution to the floating-point conversion
X-Git-Tag: version-3.47.2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=abfcdb63022e4d83dd8f7ed6285820daee11bedf;p=thirdparty%2Fsqlite.git

Yet another iteration of the solution to the floating-point conversion
problem.  This one avoids complaints about oversize double values
from -fsanitize.

FossilOrigin-Name: 07bd06b13c42edb3a3efa8f26d48823c9ffa3d5ec8d06ee21a33b6c1d29b4726
---

diff --git a/manifest b/manifest
index e0b7a98abf..dc7597a953 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C A\scleaner\sand\smore\srobust\ssolution\sto\sthe\sfloating-point\sconversion\sproblem\noriginally\sfixed\searlier\stoday.
-D 2024-12-07T19:12:41.603
+C Yet\sanother\siteration\sof\sthe\ssolution\sto\sthe\sfloating-point\sconversion\nproblem.\s\sThis\sone\savoids\scomplaints\sabout\soversize\sdouble\svalues\nfrom\s-fsanitize.
+D 2024-12-07T20:01:08.210
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -841,7 +841,7 @@ F src/trigger.c 0bb986a5b96047fd597c6aac28588853df56064e576e6b81ba777ef2ccaac461
 F src/update.c 0e01aa6a3edf9ec112b33eb714b9016a81241497b1fb7c3e74332f4f71756508
 F src/upsert.c 215328c3f91623c520ec8672c44323553f12caeb4f01b1090ebdca99fdf7b4f1
 F src/utf.c 8b29d9a5956569ea2700f869669b8ef67a9662ee5e724ff77ab3c387e27094ba
-F src/util.c 10dc2a3639c9b2393ba44ddd643a9385e22a8aab950160e3a42b76cdc7e3f883
+F src/util.c 9234bbddd2ba8ff22fc07331d34b01da6c4c4ce36ca34852e44dc746acdefa18
 F src/vacuum.c b763b6457bd058d2072ef9364832351fd8d11e8abf70cbb349657360f7d55c40
 F src/vdbe.c 1f56a0ae24115c2e37213e77cf79aa3b8c8d0366755707385564f6b8dd83d0fb
 F src/vdbe.h c2549a215898a390de6669cfa32adba56f0d7e17ba5a7f7b14506d6fd5f0c36a
@@ -2222,9 +2222,9 @@ F vsixtest/vsixtest.tcl 6195aba1f12a5e10efc2b8c0009532167be5e301abe5b31385638080
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 42aa7157f8b549d4321a8811a8223a98f877b60f032f529fd3948dfc0aa54cd7
-Q +351de57f80b73045448c71d3402d877ff5d72418b1f5fc34c8147a04f7c5cb78
-R 99f2d4cc7e69d5c0358c51b93825fdc4
+P 18b20494ce0d0f8eb87f1157245ebd728d2262f0d1d902a5934f240fc781b4e6
+Q +fc6904a508eb732b1cb5cc12321a0d637d97e1e066a022a2c93cb50595f3a86a
+R 3df4e8abea3bba7571d6c59d3633b08c
 U drh
-Z e1fe34756bd989b4f916e0f8d7127934
+Z 9ea0b936588d1ad66563ee6d841ee4e2
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 9b29617a9a..da6139762d 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-18b20494ce0d0f8eb87f1157245ebd728d2262f0d1d902a5934f240fc781b4e6
+07bd06b13c42edb3a3efa8f26d48823c9ffa3d5ec8d06ee21a33b6c1d29b4726
diff --git a/src/util.c b/src/util.c
index d553f36c74..0a2e47469e 100644
--- a/src/util.c
+++ b/src/util.c
@@ -653,15 +653,15 @@ do_atof_calc:
   }
 
   rr[0] = (double)s;
-  s2 = (u64)rr[0];
-  rr[1] = s>=s2 ? (double)(s - s2) : -(double)(s2 - s);
-  if( rr[1]>1e-10*rr[0] ){
-    /* On some floating-point processing units, doing the round
-    ** trip from u64 to double back to u64 can give a wonky value
-    ** when the original u64 is close to LARGEST_UINT64.  If we
-    ** did get an overly large error value, just set it to zero. */
+  assert( sizeof(s2)==sizeof(rr[0]) );
+  memcpy(&s2, &rr[0], sizeof(s2));
+  if( s2<=0x43efffffffffffffLL ){
+    s2 = (u64)rr[0];
+    rr[1] = s>=s2 ? (double)(s - s2) : -(double)(s2 - s);
+  }else{
     rr[1] = 0.0;
   }
+  assert( rr[1]<=1.0e-10*rr[0] );  /* Equal only when rr[0]==0.0 */
 
   if( e>0 ){
     while( e>=100  ){