From d39fbed75810fc7478842503ecb0268b85dc9c2e Mon Sep 17 00:00:00 2001
From: Uros Bizjak <ubizjak@gmail.com>
Date: Tue, 18 May 2021 15:45:54 +0200
Subject: [PATCH] i386: Fix split_double_mode with paradoxical subreg
[PR100626]
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split_double_mode calls simplify_gen_subreg, which fails for the
high half of the paradoxical subreg. Return temporary register
instead of NULL RTX in this case.
2021-05-18 Uroš Bizjak <ubizjak@gmail.com>
gcc/
PR target/100626
* config/i386/i386-expand.c (split_double_mode): Return
temporary register when simplify_gen_subreg fails with
the high half od the paradoxical subreg.
---
gcc/config/i386/i386-expand.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c
index 0fa8d45a684e..9f3d41955a2f 100644
--- a/gcc/config/i386/i386-expand.c
+++ b/gcc/config/i386/i386-expand.c
@@ -154,9 +154,13 @@ split_double_mode (machine_mode mode, rtx operands[],
lo_half[num] = simplify_gen_subreg (half_mode, op,
GET_MODE (op) == VOIDmode
? mode : GET_MODE (op), 0);
- hi_half[num] = simplify_gen_subreg (half_mode, op,
- GET_MODE (op) == VOIDmode
- ? mode : GET_MODE (op), byte);
+
+ rtx tmp = simplify_gen_subreg (half_mode, op,
+ GET_MODE (op) == VOIDmode
+ ? mode : GET_MODE (op), byte);
+ /* simplify_gen_subreg will return NULL RTX for the
+ high half of the paradoxical subreg. */
+ hi_half[num] = tmp ? tmp : gen_reg_rtx (half_mode);
}
}
}
--
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