Hi, This patch creates a new function - change_pseudo_and_mask. If recog fails, the function converts a single pseudo to the pseudo AND with a mask if the outer operator is IOR/XOR/PLUS and inner operator is ASHIFT or AND. The conversion helps pattern to match rotate and mask insn on some targets.
Bootstrapped and tested on powerpc64-linux BE and LE with no regressions. Is this okay for trunk? Any recommendations? Thanks a lot. ChangeLog 2022-07-22 Haochen Gui <guih...@linux.ibm.com> gcc/ PR target/93453 * combine.cc (change_pseudo_and_mask): New. (recog_for_combine): If recog fails, try again with the pattern modified by change_pseudo_and_mask. * config/rs6000/rs6000.md (plus_ior_xor): Remove. (anonymous split pattern for plus_ior_xor): Remove. gcc/testsuite/ PR target/93453 * gcc.target/powerpc/pr93453-2.c: New. * gcc.target/powerpc/rlwimi-2.c: Both 32/64 bit platforms generate the same number of rlwimi. Reset the counter. patch.diff diff --git a/gcc/combine.cc b/gcc/combine.cc index a5fabf397f7..e1c1aa7da1c 100644 --- a/gcc/combine.cc +++ b/gcc/combine.cc @@ -11599,6 +11599,48 @@ change_zero_ext (rtx pat) return changed; } +/* When the outer code of set_src is IOR/XOR/PLUS and the inner code is + ASHIFT/AND, convert a pseudo to pseudo AND with a mask if its nonzero_bits + is less than its mode mask. The nonzero_bits in later passes is not a + superset of what is known in combine pass. So an insn with nonzero_bits + can't be recoged later. */ +static bool +change_pseudo_and_mask (rtx pat) +{ + rtx src = SET_SRC (pat); + if ((GET_CODE (src) == IOR + || GET_CODE (src) == XOR + || GET_CODE (src) == PLUS) + && (((GET_CODE (XEXP (src, 0)) == ASHIFT + || GET_CODE (XEXP (src, 0)) == AND) + && REG_P (XEXP (src, 1))))) + { + rtx reg = XEXP (src, 1); + machine_mode mode = GET_MODE (reg); + unsigned HOST_WIDE_INT nonzero = nonzero_bits (reg, mode); + if (nonzero < GET_MODE_MASK (mode)) + { + int shift; + + if (GET_CODE (XEXP (src, 0)) == ASHIFT) + shift = INTVAL (XEXP (XEXP (src, 0), 1)); + else + shift = ctz_hwi (INTVAL (XEXP (XEXP (src, 0), 1))); + + if (shift > 0 + && (HOST_WIDE_INT_1U << shift) - 1 >= nonzero) + { + unsigned HOST_WIDE_INT mask = (HOST_WIDE_INT_1U << shift) - 1; + rtx x = gen_rtx_AND (mode, reg, GEN_INT (mask)); + SUBST (XEXP (SET_SRC (pat), 1), x); + maybe_swap_commutative_operands (SET_SRC (pat)); + return true; + } + } + } + return false; +} + /* Like recog, but we receive the address of a pointer to a new pattern. We try to match the rtx that the pointer points to. If that fails, we may try to modify or replace the pattern, @@ -11646,7 +11688,10 @@ recog_for_combine (rtx *pnewpat, rtx_insn *insn, rtx *pnotes) } } else - changed = change_zero_ext (pat); + { + changed = change_pseudo_and_mask (pat); + changed |= change_zero_ext (pat); + } } else if (GET_CODE (pat) == PARALLEL) { diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md index 1367a2cb779..2bd6bd5f908 100644 --- a/gcc/config/rs6000/rs6000.md +++ b/gcc/config/rs6000/rs6000.md @@ -4207,24 +4207,6 @@ (define_insn_and_split "*rotl<mode>3_insert_3_<code>" (ior:GPR (and:GPR (match_dup 3) (match_dup 4)) (ashift:GPR (match_dup 1) (match_dup 2))))]) -(define_code_iterator plus_ior_xor [plus ior xor]) - -(define_split - [(set (match_operand:GPR 0 "gpc_reg_operand") - (plus_ior_xor:GPR (ashift:GPR (match_operand:GPR 1 "gpc_reg_operand") - (match_operand:SI 2 "const_int_operand")) - (match_operand:GPR 3 "gpc_reg_operand")))] - "nonzero_bits (operands[3], <MODE>mode) - < HOST_WIDE_INT_1U << INTVAL (operands[2])" - [(set (match_dup 0) - (ior:GPR (and:GPR (match_dup 3) - (match_dup 4)) - (ashift:GPR (match_dup 1) - (match_dup 2))))] -{ - operands[4] = GEN_INT ((HOST_WIDE_INT_1U << INTVAL (operands[2])) - 1); -}) - (define_insn "*rotlsi3_insert_4" [(set (match_operand:SI 0 "gpc_reg_operand" "=r") (ior:SI (and:SI (match_operand:SI 3 "gpc_reg_operand" "0") diff --git a/gcc/testsuite/gcc.target/powerpc/pr93453-2.c b/gcc/testsuite/gcc.target/powerpc/pr93453-2.c new file mode 100644 index 00000000000..a83a6511653 --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/pr93453-2.c @@ -0,0 +1,19 @@ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ + +long foo (char a, long b) +{ + long c = a; + c = c | (b << 12); + return c; +} + +long bar (long b, char a) +{ + long c = a; + long m = -4096; + c = c | (b & m); + return c; +} + +/* { dg-final { scan-assembler-times {\mrl[wd]imi\M} 2 } } */ diff --git a/gcc/testsuite/gcc.target/powerpc/rlwimi-2.c b/gcc/testsuite/gcc.target/powerpc/rlwimi-2.c index bafa371db73..d4dadacc6cc 100644 --- a/gcc/testsuite/gcc.target/powerpc/rlwimi-2.c +++ b/gcc/testsuite/gcc.target/powerpc/rlwimi-2.c @@ -8,8 +8,7 @@ /* { dg-final { scan-assembler-times {(?n)^\s+mr} 11 { target lp64 } } } */ /* { dg-final { scan-assembler-times {(?n)^\s+rldicl} 7790 { target lp64 } } } */ -/* { dg-final { scan-assembler-times {(?n)^\s+rlwimi} 1692 { target ilp32 } } } */ -/* { dg-final { scan-assembler-times {(?n)^\s+rlwimi} 1666 { target lp64 } } } */ +/* { dg-final { scan-assembler-times {(?n)^\s+rlwimi} 1692 } } */ /* { dg-final { scan-assembler-times {(?n)^\s+mulli} 5036 } } */