From: Maciej W. Rozycki <macro@embecosm.com>
Date: Wed, 22 Nov 2023 01:18:27 +0000 (+0000)
Subject: RISC-V: Also accept constants for T-Head cond-move comparison operands
X-Git-Tag: basepoints/gcc-15~4420
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eeb112542f9a93974ee17d582ba649c50af95c86;p=thirdparty%2Fgcc.git

RISC-V: Also accept constants for T-Head cond-move comparison operands

There is no need for the requirement for conditional-move comparison
operands to be stricter for T-Head targets than for other targets and
limit them to registers only.  Constants will be reloaded if required
just as with branches or other-target conditional-move operations and
there is no extra overhead specific to the T-Head case.  This enables
more opportunities for a branchless sequence to be produced.

	gcc/
	* config/riscv/riscv.cc (riscv_expand_conditional_move): Also
	accept constants for T-Head comparison operands.
---

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index e418ccc90613..ac2e76f4bedf 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -4126,8 +4126,8 @@ riscv_expand_conditional_move (rtx dest, rtx op, rtx cons, rtx alt)
       && reg_or_0_operand (cons, mode)
       && reg_or_0_operand (alt, mode)
       && (GET_MODE (op) == mode || GET_MODE (op) == E_VOIDmode)
-      && GET_MODE (op0) == mode
-      && GET_MODE (op1) == mode
+      && (GET_MODE (op0) == mode || CONST_INT_P (op0))
+      && (GET_MODE (op1) == mode || CONST_INT_P (op1))
       && (code == EQ || code == NE))
     need_eq_ne_p = true;