From 6c71fd461daf8161fce6e1d4242a1e8b33f21271 Mon Sep 17 00:00:00 2001
From: florian <florian@freepascal.org>
Date: Fri, 24 Jan 2020 21:39:07 +0000
Subject: [PATCH]   * avoid internalerror for dec/inc(...,v) with
 v>high(int64), resolves #35298

git-svn-id: trunk@44031 -
---
 .gitattributes          |  1 +
 compiler/ncginl.pas     |  4 +++-
 tests/webtbs/tw35298.pp | 16 ++++++++++++++++
 3 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 tests/webtbs/tw35298.pp

diff --git a/.gitattributes b/.gitattributes
index 88862afaad..c4a9a7003f 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -17904,6 +17904,7 @@ tests/webtbs/tw3523.pp svneol=native#text/plain
 tests/webtbs/tw35233.pp svneol=native#text/plain
 tests/webtbs/tw35272.pp svneol=native#text/plain
 tests/webtbs/tw3529.pp svneol=native#text/plain
+tests/webtbs/tw35298.pp svneol=native#text/pascal
 tests/webtbs/tw3531.pp svneol=native#text/plain
 tests/webtbs/tw3533.pp svneol=native#text/plain
 tests/webtbs/tw3534.pp svneol=native#text/plain
diff --git a/compiler/ncginl.pas b/compiler/ncginl.pas
index b2eb48cede..acc44df296 100644
--- a/compiler/ncginl.pas
+++ b/compiler/ncginl.pas
@@ -451,7 +451,9 @@ implementation
             begin
 {$if not defined(cpu64bitalu) and not defined(cpuhighleveltarget)}
               if def_cgsize(left.resultdef) in [OS_64,OS_S64] then
-                cg64.a_op64_const_loc(current_asmdata.CurrAsmList,addsubop[inlinenumber],def_cgsize(left.resultdef),addvalue,tcallparanode(left).left.location)
+                { use addvalue.svalue here to avoid an internal error if addvalue is unsigned and overflows int64, see #35298,
+                  we are only interested in the bit pattern here }
+                cg64.a_op64_const_loc(current_asmdata.CurrAsmList,addsubop[inlinenumber],def_cgsize(left.resultdef),addvalue.svalue,tcallparanode(left).left.location)
               else
 {$endif not cpu64bitalu and not cpuhighleveltarget}
                 hlcg.a_op_const_loc(current_asmdata.CurrAsmList,addsubop[inlinenumber],left.resultdef,
diff --git a/tests/webtbs/tw35298.pp b/tests/webtbs/tw35298.pp
new file mode 100644
index 0000000000..8377b58b84
--- /dev/null
+++ b/tests/webtbs/tw35298.pp
@@ -0,0 +1,16 @@
+{$MODE DELPHI}
+{$RANGECHECKS OFF}
+{$OVERFLOWCHECKS OFF}
+
+function SplitMix64(var X: UInt64) : UInt64;
+var
+  Z: UInt64;
+begin
+  Inc(X, UInt64($9E3779B97F4A7C15));
+  Z := (X xor (X shr 30)) * UInt64($BF58476D1CE4E5B9);
+  Z := (Z xor (Z shr 27)) * UInt64($94D049BB133111EB);
+  Result := Z xor (Z shr 31);
+end;
+
+begin
+end.