Hi,Richard. Do you mean add the check as follows ? if (VECTOR_CST_NELTS_PER_PATTERN (arg1) == 1 && VECTOR_CST_NELTS_PER_PATTERN (arg2) == 3 && integer_zerop (VECTOR_CST_ELT (arg1, 0))) step_ok_p = (code == BIT_AND_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR); else if (VECTOR_CST_NELTS_PER_PATTERN (arg2) == 1 && VECTOR_CST_NELTS_PER_PATTERN (arg1) == 3 && integer_zerop (VECTOR_CST_ELT (arg2, 0))) step_ok_p = (code == BIT_AND_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR); juzhe.zhong@rivai.ai From: Richard Biener Date: 2023-12-19 16:15 To: 钟居哲 CC: rdapp.gcc; gcc-patches; pan2.li; richard.sandiford; richard.guenther; Andrew Pinski Subject: Re: [PATCH] fold-const: Handle AND, IOR, XOR with stepped vectors [PR112971]. On Tue, 19 Dec 2023, ??? wrote: > Thanks Robin send initial patch to fix this ICE bug. > > CC to Richard S, Richard B, and Andrew. Just one comment, it seems that VECTOR_CST_STEPPED_P should implicitly include VECTOR_CST_DUPLICATE_P since it would be a step of zero (but as implemented it doesn't catch this). Looking at the implementation it's odd that we can handle VECTOR_CST_NELTS_PER_PATTERN == 1 (duplicate) and == 3 (stepped) but not == 2 (not sure what that would be). Maybe the tests can be re-formulated in terms of VECTOR_CST_NELTS_PER_PATTERN? Richard. > Thanks. > > > > juzhe.zhong@rivai.ai > > From: Robin Dapp > Date: 2023-12-19 03:50 > To: gcc-patches > CC: rdapp.gcc; Li, Pan2; juzhe.zhong@rivai.ai > Subject: [PATCH] fold-const: Handle AND, IOR, XOR with stepped vectors [PR112971]. > Hi, > > found in PR112971, this patch adds folding support for bitwise operations > of const duplicate zero vectors and stepped vectors. > On riscv we have the situation that a folding would perpetually continue > without simplifying because e.g. {0, 0, 0, ...} & {7, 6, 5, ...} would > not fold to {0, 0, 0, ...}. > > Bootstrapped and regtested on x86 and aarch64, regtested on riscv. > > I won't be available to respond quickly until next year. Pan or Juzhe, > as discussed, feel free to continue with possible revisions. > > Regards > Robin > > > gcc/ChangeLog: > > PR middle-end/112971 > > * fold-const.cc (const_binop): Handle > zerop@1 AND/IOR/XOR VECT_CST_STEPPED_P@2 > > gcc/testsuite/ChangeLog: > > * gcc.target/riscv/rvv/autovec/pr112971.c: New test. > --- > gcc/fold-const.cc | 14 +++++++++++++- > .../gcc.target/riscv/rvv/autovec/pr112971.c | 18 ++++++++++++++++++ > 2 files changed, 31 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112971.c > > diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc > index f5d68ac323a..43ed097bf5c 100644 > --- a/gcc/fold-const.cc > +++ b/gcc/fold-const.cc > @@ -1653,8 +1653,20 @@ const_binop (enum tree_code code, tree arg1, tree arg2) > { > tree type = TREE_TYPE (arg1); > bool step_ok_p; > + > + /* AND, IOR as well as XOR with a zerop can be handled directly. */ > if (VECTOR_CST_STEPPED_P (arg1) > - && VECTOR_CST_STEPPED_P (arg2)) > + && VECTOR_CST_DUPLICATE_P (arg2) > + && integer_zerop (VECTOR_CST_ELT (arg2, 0))) > + step_ok_p = code == BIT_AND_EXPR || code == BIT_IOR_EXPR > + || code == BIT_XOR_EXPR; > + else if (VECTOR_CST_STEPPED_P (arg2) > + && VECTOR_CST_DUPLICATE_P (arg1) > + && integer_zerop (VECTOR_CST_ELT (arg1, 0))) > + step_ok_p = code == BIT_AND_EXPR || code == BIT_IOR_EXPR > + || code == BIT_XOR_EXPR; > + else if (VECTOR_CST_STEPPED_P (arg1) > + && VECTOR_CST_STEPPED_P (arg2)) > /* We can operate directly on the encoding if: > a3 - a2 == a2 - a1 && b3 - b2 == b2 - b1 > diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112971.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112971.c > new file mode 100644 > index 00000000000..816ebd3c493 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112971.c > @@ -0,0 +1,18 @@ > +/* { dg-do compile } */ > +/* { dg-options "-march=rv64gcv_zvl256b -mabi=lp64d -O3 -fno-vect-cost-model" } */ > + > +int a; > +short b[9]; > +char c, d; > +void e() { > + d = 0; > + for (;; d++) { > + if (b[d]) > + break; > + a = 8; > + for (; a >= 0; a--) { > + char *f = &c; > + *f &= d == (a & d); > + } > + } > +} > -- Richard Biener SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)