From 0340177d54d08b6375391ba164a878e6a596275e Mon Sep 17 00:00:00 2001 From: Andrew Pinski Date: Tue, 29 Jul 2025 21:49:16 -0700 Subject: [PATCH v2] simplify-rtx: Add `(subreg (not a))` simplification for word_mode [PR121308] Right now in simplify_subreg, there is code to try to simplify for word_mode with the binary bitwise operators. The unary bitwise operator is not handle, this causes an odd mix match and the new self testing code that was added with r16-2614-g965564eafb721f was not expecting. The self testing code was for testing the newly added code but since there was already code that handles word_mode, we hit the mismatch but only for targets where word_mode is SImode (or smaller). This adds the code to handle `not` in a similar fashion as the other bitwise operators for word_mode. Changes since v1: * v2: add `&& SCALAR_INT_MODE_P (innermode)` to the conditional. Bootstrapped and tested on x86_64-linux-gnu. PR rtl-optimization/121308 gcc/ChangeLog: * simplify-rtx.cc (simplify_context::simplify_subreg): Handle subreg of `not` with word_mode to make it symmetric with the other bitwise operators. Signed-off-by: Andrew Pinski --- gcc/simplify-rtx.cc | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc index 442da9f40fa..c723a07f06b 100644 --- a/gcc/simplify-rtx.cc +++ b/gcc/simplify-rtx.cc @@ -8344,6 +8344,15 @@ simplify_context::simplify_subreg (machine_mode outermode, rtx op, return simplify_gen_binary (GET_CODE (op), outermode, op0, op1); } + /* Attempt to simplify WORD_MODE SUBREGs of unary bitwise expression. */ + if (outermode == word_mode && GET_CODE (op) == NOT + && SCALAR_INT_MODE_P (innermode)) + { + rtx op0 = simplify_subreg (outermode, XEXP (op, 0), innermode, byte); + if (op0) + return simplify_gen_unary (GET_CODE (op), outermode, op0, outermode); + } + scalar_int_mode int_outermode, int_innermode; if (is_a (outermode, &int_outermode) && is_a (innermode, &int_innermode) -- 2.43.0