From c17f5de254be9dc3cb911c5b9e573291b1bd6928 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Thu, 1 Jun 2023 10:41:49 +0200
Subject: [PATCH] Fix miscompilation of guard with `or`

Closes #7370
---
 lib/compiler/src/beam_ssa_bool.erl |  5 ++++-
 lib/compiler/test/guard_SUITE.erl  | 11 +++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/compiler/src/beam_ssa_bool.erl b/lib/compiler/src/beam_ssa_bool.erl
index b0d4ab04ffe6..7d267dc072ca 100644
--- a/lib/compiler/src/beam_ssa_bool.erl
+++ b/lib/compiler/src/beam_ssa_bool.erl
@@ -366,7 +366,10 @@ pre_opt_is([#b_set{op={succeeded,_},dst=Dst,args=Args0}=I0|Is],
             Sub = Sub0#{Dst=>#b_literal{val=true}},
             pre_opt_is(Is, Reached, Sub, Acc);
         false ->
-            pre_opt_is(Is, Reached, Sub0, [I|Acc])
+            %% Don't remember boolean expressions that can potentially fail,
+            %% because that can cause unsafe optimizations.
+            Sub = maps:remove(Arg, Sub0),
+            pre_opt_is(Is, Reached, Sub, [I|Acc])
     end;
 pre_opt_is([#b_set{dst=Dst,args=Args0}=I0|Is], Reached, Sub0, Acc) ->
     Args = sub_args(Args0, Sub0),
diff --git a/lib/compiler/test/guard_SUITE.erl b/lib/compiler/test/guard_SUITE.erl
index 047bebe978b9..88c6e70bd645 100644
--- a/lib/compiler/test/guard_SUITE.erl
+++ b/lib/compiler/test/guard_SUITE.erl
@@ -2619,6 +2619,7 @@ beam_bool_SUITE(_Config) ->
     gh_6164(),
     gh_6184(),
     gh_7339(),
+    gh_7370(),
     ok.
 
 before_and_inside_if() ->
@@ -3177,6 +3178,16 @@ do_gh_7339(M) when is_number(M) or (not is_map(M#{a => b})) ->
 do_gh_7339(_) ->
   b.
 
+gh_7370() ->
+    b = gh_7370(id(42)),
+    b = gh_7370(id(42.0)),
+    ok.
+
+gh_7370(A) when (not (not is_float(A))) =/= ((ok and ok) or true) ->
+    a;
+gh_7370(_) ->
+    b.
+
 %%%
 %%% End of beam_bool_SUITE tests.
 %%%