[gcc r14-10187] AVR: target/114975 - Add combine-pattern for __popcountqi2.

[Georg-Johann Lay via Gcc-cvs]

https://gcc.gnu.org/g:4ef09dd8ce8866e4f64dd918890c97a67af8fd15

commit r14-10187-g4ef09dd8ce8866e4f64dd918890c97a67af8fd15
Author: Georg-Johann Lay <a...@gjlay.de>
Date:   Tue May 7 19:39:55 2024 +0200

    AVR: target/114975 - Add combine-pattern for __popcountqi2.
    
            PR target/114975
    gcc/
            * config/avr/avr.md: Add combine pattern for
            8-bit popcount detection.
    
    gcc/testsuite/
            * gcc.target/avr/pr114975-popcount.c: New test.
    
    (cherry picked from commit c8f4bbb824fafecf021a802324cd79e64b03b947)

Diff:
---
 gcc/config/avr/avr.md                            | 13 +++++++++++++
 gcc/testsuite/gcc.target/avr/pr114975-popcount.c | 17 +++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/gcc/config/avr/avr.md b/gcc/config/avr/avr.md
index 97f42be7729c..36fe384828f9 100644
--- a/gcc/config/avr/avr.md
+++ b/gcc/config/avr/avr.md
@@ -8527,6 +8527,19 @@
     operands[2] = gen_reg_rtx (HImode);
   })
 
+(define_insn_and_split "*popcounthi2.split8"
+  [(set (reg:HI 24)
+        (zero_extend:HI (popcount:QI (match_operand:QI 0 
"register_operand"))))]
+  "! reload_completed"
+  { gcc_unreachable(); }
+  "&& 1"
+  [(set (reg:QI 24)
+        (match_dup 0))
+   (set (reg:QI 24)
+        (popcount:QI (reg:QI 24)))
+   (set (reg:QI 25)
+        (const_int 0))])
+
 (define_insn_and_split "*popcounthi2.libgcc_split"
   [(set (reg:HI 24)
         (popcount:HI (reg:HI 24)))]
diff --git a/gcc/testsuite/gcc.target/avr/pr114975-popcount.c 
b/gcc/testsuite/gcc.target/avr/pr114975-popcount.c
new file mode 100644
index 000000000000..87eb56b56c5a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/avr/pr114975-popcount.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-Os" } */
+
+typedef __UINT8_TYPE__ uint8_t;
+
+uint8_t use_pop1 (int y, uint8_t x)
+{
+    return 1 + __builtin_popcount (x);
+}
+
+uint8_t use_pop2 (uint8_t x)
+{
+       x += 1;
+    return 1 - __builtin_popcount (x);
+}
+
+/* { dg-final { scan-assembler-times "__popcountqi2" 2 } } */