Support pandn for V1TI mode (i.e. *andnotv1ti3).

This simple patch allows the i386 backend to generate pandn instructions
for V1TI mode.  Currently, the testcase:

typedef unsigned __int128 v1ti __attribute__ ((__vector_size__ (16)));
v1ti andnot1(v1ti x, v1ti y) { return ~x & y; }

generates with -O2

        pcmpeqd %xmm2, %xmm2
        pxor    %xmm2, %xmm0
        pand    %xmm1, %xmm0
        ret

with this patch, we now generate:

        pandn   %xmm1, %xmm0
        ret

It turns out that there are currently three (near) duplicates of the
logic for andn/pandn/vandn/vpandn in i386/sse.md: one for floating point
vectors (MODEF), one for integer vectors (VI) and a third for TFmode.
Rather than introduce a fourth copy, this patch introduces a new mode
iterator to share/reuse the TFmode define_insn to also handle V1TI.

2022-04-06  Roger Sayle  <roger@nextmovesoftware.com>

gcc/ChangeLog
	* config/i386/sse.md (ANDNOT_MODE): New mode iterator for TF and V1TI.
	(*andnottf3): Replace with...
	(*andnot<mode>3): New define_insn using ANDNOT_MODE.

gcc/testsuite/ChangeLog
	* gcc.target/i386/sse2-v1ti-andnot.c: New test case.

diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index 1f9c496..a852c16 100644 (file)
--- a/gcc/config/i386/sse.md
+++ b/gcc/config/i386/sse.md
@@ -4923,11 +4923,14 @@
              ]
              (const_string "<ssevecmode>")))])
 
-(define_insn "*andnottf3"
-  [(set (match_operand:TF 0 "register_operand" "=x,x,v,v")
-       (and:TF
-         (not:TF (match_operand:TF 1 "register_operand" "0,x,v,v"))
-         (match_operand:TF 2 "vector_operand" "xBm,xm,vm,v")))]
+;; Modes for andnot3 not covered by VI and MODEF.
+(define_mode_iterator ANDNOT_MODE [TF V1TI])
+
+(define_insn "*andnot<mode>3"
+  [(set (match_operand:ANDNOT_MODE 0 "register_operand" "=x,x,v,v")
+       (and:ANDNOT_MODE
+         (not:ANDNOT_MODE (match_operand:ANDNOT_MODE 1 "register_operand" "0,x,v,v"))
+         (match_operand:ANDNOT_MODE 2 "vector_operand" "xBm,xm,vm,v")))]
   "TARGET_SSE"
 {
   char buf[128];

diff --git a/gcc/testsuite/gcc.target/i386/sse2-v1ti-andnot.c b/gcc/testsuite/gcc.target/i386/sse2-v1ti-andnot.c
new file mode 100644 (file)
index 0000000..ae4cb02
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/sse2-v1ti-andnot.c
@@ -0,0 +1,11 @@
+/* { dg-do compile { target int128 } } */
+/* { dg-options "-O2 -msse2" } */
+
+typedef __int128 v1ti __attribute__ ((__vector_size__ (16)));
+
+v1ti andnot1(v1ti x, v1ti y) { return ~x & y; }
+v1ti andnot2(v1ti x, v1ti y) { return x & ~y; }
+
+/* { dg-final { scan-assembler-times "pandn" 2 } } */
+/* { dg-final { scan-assembler-not "pcmpeqd" } } */
+/* { dg-final { scan-assembler-not "pxor" } } */