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| author | Takayuki 'January June' Suwa <jjsuwa_sys3175@yahoo.co.jp> | 2022-05-29 19:55:44 +0900 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2022-06-09 15:07:47 -0700 |
| commit | e44e7face13f38f9b228e2619786ba0add9ef77b (patch) | |
| tree | 356fa8e12101fbb4b3a7c1bb47dbb13c9f7dcbaf | |
| parent | 9777d446e2148ef9a6e9f35db3f4eab99ee8812c (diff) | |
| download | gcc-e44e7face13f38f9b228e2619786ba0add9ef77b.zip gcc-e44e7face13f38f9b228e2619786ba0add9ef77b.tar.gz gcc-e44e7face13f38f9b228e2619786ba0add9ef77b.tar.bz2 | |
xtensa: Optimize '(~x & y)' to '((x & y) ^ y)'
In Xtensa ISA, there is no single machine instruction that calculates unary
bitwise negation.
gcc/ChangeLog:
* config/xtensa/xtensa.md (*andsi3_bitcmpl):
New insn_and_split pattern.
gcc/testsuite/ChangeLog:
* gcc.target/xtensa/check_zero_byte.c: New.
| -rw-r--r-- | gcc/config/xtensa/xtensa.md | 20 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/xtensa/check_zero_byte.c | 9 |
2 files changed, 29 insertions, 0 deletions
diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md index fd80fdd..3afc252 100644 --- a/gcc/config/xtensa/xtensa.md +++ b/gcc/config/xtensa/xtensa.md @@ -601,6 +601,26 @@ (set_attr "mode" "SI") (set_attr "length" "3,3")]) +(define_insn_and_split "*andsi3_bitcmpl" + [(set (match_operand:SI 0 "register_operand" "=a") + (and:SI (not:SI (match_operand:SI 1 "register_operand" "r")) + (match_operand:SI 2 "register_operand" "r")))] + "" + "#" + "&& can_create_pseudo_p ()" + [(set (match_dup 3) + (and:SI (match_dup 1) + (match_dup 2))) + (set (match_dup 0) + (xor:SI (match_dup 3) + (match_dup 2)))] +{ + operands[3] = gen_reg_rtx (SImode); +} + [(set_attr "type" "arith") + (set_attr "mode" "SI") + (set_attr "length" "6")]) + (define_insn "iorsi3" [(set (match_operand:SI 0 "register_operand" "=a") (ior:SI (match_operand:SI 1 "register_operand" "%r") diff --git a/gcc/testsuite/gcc.target/xtensa/check_zero_byte.c b/gcc/testsuite/gcc.target/xtensa/check_zero_byte.c new file mode 100644 index 0000000..6a04aae --- /dev/null +++ b/gcc/testsuite/gcc.target/xtensa/check_zero_byte.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-O" } */ + +int check_zero_byte(int v) +{ + return (v - 0x01010101) & ~v & 0x80808080; +} + +/* { dg-final { scan-assembler-not "movi" } } */ |