From: Maciej W. Rozycki <macro@embecosm.com>
Date: Wed, 22 Nov 2023 01:18:25 +0000 (+0000)
Subject: RISC-V: Also invert the cond-move condition for GEU and LEU
X-Git-Tag: basepoints/gcc-15~4426
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=db9d825b212994e89dabc710c61944552eb1fe90;p=thirdparty%2Fgcc.git

RISC-V: Also invert the cond-move condition for GEU and LEU

Update `riscv_expand_conditional_move' and handle the missing GEU and
LEU operators there, avoiding an extraneous conditional set operation,
such as with this output:

	sgtu	a0,a0,a1
	seqz	a1,a0
	czero.eqz	a3,a3,a1
	czero.nez	a1,a2,a1
	or	a0,a1,a3

produced when optimizing for Zicond targets from:

int
movsigtu (int w, int x, int y, int z)
{
  return w > x ? y : z;
}

These operators can be inverted producing optimal code such as this:

	sgtu	a1,a0,a1
	czero.nez	a3,a3,a1
	czero.eqz	a1,a2,a1
	or	a0,a1,a3

which this change causes to happen.

	gcc/
	* config/riscv/riscv.cc (riscv_expand_conditional_move): Also
	invert the condition for GEU and LEU.
---

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index e5f09c024ccf..c7de7720c39a 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -4171,7 +4171,7 @@ riscv_expand_conditional_move (rtx dest, rtx op, rtx cons, rtx alt)
 	  /* If riscv_expand_int_scc inverts the condition, then it will
 	     flip the value of INVERT.  We need to know where so that
 	     we can adjust it for our needs.  */
-	  if (code == LE || code == GE)
+	  if (code == LE || code == LEU || code == GE || code == GEU)
 	    invert_ptr = &invert;
 
 	  /* Emit an scc like instruction into a temporary