From: David Faust <david.faust@oracle.com>
Date: Mon, 21 Aug 2023 20:34:08 +0000 (-0700)
Subject: bpf: neg instruction does not accept an immediate
X-Git-Tag: basepoints/gcc-15~6771
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e2c42860b6bad30bad8dd12fd0e25dc55646a69c;p=thirdparty%2Fgcc.git

bpf: neg instruction does not accept an immediate

The BPF virtual machine does not support neg nor neg32 instructions with
an immediate.

The erroneous instructions were removed from binutils:
https://sourceware.org/pipermail/binutils/2023-August/129135.html

Change the define_insn so that an immediate cannot be accepted.

From testing, a neg-immediate was probably never chosen over a
mov-immediate anyway.

gcc/

	* config/bpf/bpf.md (neg): Second operand must be a register.
---

diff --git a/gcc/config/bpf/bpf.md b/gcc/config/bpf/bpf.md
index a64de1095eda..e87d72182bb8 100644
--- a/gcc/config/bpf/bpf.md
+++ b/gcc/config/bpf/bpf.md
@@ -163,8 +163,8 @@
 
 ;;; Negation
 (define_insn "neg<AM:mode>2"
-  [(set (match_operand:AM         0 "register_operand"   "=r,r")
-        (neg:AM (match_operand:AM 1 "reg_or_imm_operand" " 0,I")))]
+  [(set (match_operand:AM         0 "register_operand" "=r")
+        (neg:AM (match_operand:AM 1 "register_operand" " 0")))]
   ""
   "{neg<msuffix>\t%0|%w0 = -%w1}"
   [(set_attr "type" "<mtype>")])