i386: Fix endless recursion in ix86_expand_vector_init_general with MMX [PR110152]

I'm getting
+FAIL: gcc.target/i386/3dnow-1.c (internal compiler error: Segmentation fault signal terminated program cc1)
+FAIL: gcc.target/i386/3dnow-1.c (test for excess errors)
+FAIL: gcc.target/i386/3dnow-2.c (internal compiler error: Segmentation fault signal terminated program cc1)
+FAIL: gcc.target/i386/3dnow-2.c (test for excess errors)
+FAIL: gcc.target/i386/mmx-1.c (internal compiler error: Segmentation fault signal terminated program cc1)
+FAIL: gcc.target/i386/mmx-1.c (test for excess errors)
+FAIL: gcc.target/i386/mmx-2.c (internal compiler error: Segmentation fault signal terminated program cc1)
+FAIL: gcc.target/i386/mmx-2.c (test for excess errors)
regressions on i686-linux since r14-1166.  The problem is when
ix86_expand_vector_init_general is called with mmx_ok = true and
mode = V4HImode, it newly recurses with mmx_ok = false and mode = V2SImode,
but as mmx_ok is false and !TARGET_SSE, we recurse again with the same
arguments (ok, fresh new tmp and vals) infinitely.
The following patch fixes that by passing mmx_ok to that recursive call.
For n_words == 4 it isn't needed, because we only care about mmx_ok for
V2SImode or V2SFmode and no other modes.

2023-06-08  Jakub Jelinek  <jakub@redhat.com>

	PR target/110152
	* config/i386/i386-expand.cc (ix86_expand_vector_init_general): For
	n_words == 2 recurse with mmx_ok as first argument rather than false.

diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 697eb475f486ed2574183f1ab54f287c59701374..def060ab562fbe6075ddf54c24ef490d39046b38 100644 (file)
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -16376,7 +16376,7 @@ quarter:
          machine_mode concat_mode = tmp_mode == DImode ? V2DImode : V2SImode;
          rtx tmp = gen_reg_rtx (concat_mode);
          vals = gen_rtx_PARALLEL (concat_mode, gen_rtvec_v (2, words));
-         ix86_expand_vector_init_general (false, concat_mode, tmp, vals);
+         ix86_expand_vector_init_general (mmx_ok, concat_mode, tmp, vals);
          emit_move_insn (target, gen_lowpart (mode, tmp));
        }
       else if (n_words == 4)