beam_ssa_pre_codegen: Don't use z registers for 'xor' and 'is_record'

There is no easy way to convert xor or is_record/2 to test operations.

1 files changed, 8 insertions, 0 deletions

diff --git a/lib/compiler/src/beam_ssa_pre_codegen.erl b/lib/compiler/src/beam_ssa_pre_codegen.erl
index b940c0fdc2..fa1b7bb71e 100644
--- a/lib/compiler/src/beam_ssa_pre_codegen.erl
+++ b/lib/compiler/src/beam_ssa_pre_codegen.erl
@@ -2008,6 +2008,14 @@ reserve_zreg([#b_set{op={bif,tuple_size},dst=Dst},
 reserve_zreg([#b_set{op={bif,tuple_size},dst=Dst}],
              #b_switch{}, ShortLived, A) ->
     reserve_zreg_1(Dst, ShortLived, A);
+reserve_zreg([#b_set{op={bif,'xor'}}], _Last, _ShortLived, A) ->
+    %% There is no short, easy way to rewrite 'xor' to a series of
+    %% test instructions.
+    A;
+reserve_zreg([#b_set{op={bif,is_record}}], _Last, _ShortLived, A) ->
+    %% There is no short, easy way to rewrite is_record/2 to a series of
+    %% test instructions.
+    A;
 reserve_zreg([#b_set{op=Op,dst=Dst}|Is], Last, ShortLived, A0) ->
     IsZReg = case Op of
                  bs_match_string -> true;