From: Richard Sandiford Date: Mon, 5 Aug 2019 16:46:58 +0000 (+0000) Subject: Fold MASK_LOAD/STORE with an all-true mask X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=868363d4f52df19d8d5e9529b8906fa25c8d0c95;p=gcc.git Fold MASK_LOAD/STORE with an all-true mask This patch folds IFN_MASK_LOAD and IFN_MASK_STOREs to normal accesses if the mask is all-true. This can happen for fully-masked loops that didn't actually need to be (which could be handled by the vectoriser instead), or for unrolled fully-masked loops whose first iteration is guaranteed to operate on a full vector. It's also useful when the accesses are generated directly by intrinsics (to follow for SVE). 2019-08-05 Richard Sandiford gcc/ * gimple-fold.c (gimple_fold_mask_load_store_mem_ref) (gimple_fold_mask_load, gimple_fold_mask_store): New functions. (gimple_fold_call): Use them to fold IFN_MASK_LOAD and IFN_MASK_STORE. gcc/testsuite/ * gcc.target/aarch64/sve/mask_load_1.c: New test. From-SVN: r274118 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 3d3a2fad904..26ada9c9991 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2019-08-05 Richard Sandiford + + * gimple-fold.c (gimple_fold_mask_load_store_mem_ref) + (gimple_fold_mask_load, gimple_fold_mask_store): New functions. + (gimple_fold_call): Use them to fold IFN_MASK_LOAD and + IFN_MASK_STORE. + 2019-08-05 Richard Sandiford * gimple.h (gimple_move_vops): Declare. diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index c3128e75d8b..fc57fb45e3a 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -4180,6 +4180,63 @@ arith_overflowed_p (enum tree_code code, const_tree type, return wi::min_precision (wres, sign) > TYPE_PRECISION (type); } +/* If IFN_MASK_LOAD/STORE call CALL is unconditional, return a MEM_REF + for the memory it references, otherwise return null. VECTYPE is the + type of the memory vector. */ + +static tree +gimple_fold_mask_load_store_mem_ref (gcall *call, tree vectype) +{ + tree ptr = gimple_call_arg (call, 0); + tree alias_align = gimple_call_arg (call, 1); + tree mask = gimple_call_arg (call, 2); + if (!tree_fits_uhwi_p (alias_align) || !integer_all_onesp (mask)) + return NULL_TREE; + + unsigned HOST_WIDE_INT align = tree_to_uhwi (alias_align) * BITS_PER_UNIT; + if (TYPE_ALIGN (vectype) != align) + vectype = build_aligned_type (vectype, align); + tree offset = build_zero_cst (TREE_TYPE (alias_align)); + return fold_build2 (MEM_REF, vectype, ptr, offset); +} + +/* Try to fold IFN_MASK_LOAD call CALL. Return true on success. */ + +static bool +gimple_fold_mask_load (gimple_stmt_iterator *gsi, gcall *call) +{ + tree lhs = gimple_call_lhs (call); + if (!lhs) + return false; + + if (tree rhs = gimple_fold_mask_load_store_mem_ref (call, TREE_TYPE (lhs))) + { + gassign *new_stmt = gimple_build_assign (lhs, rhs); + gimple_set_location (new_stmt, gimple_location (call)); + gimple_move_vops (new_stmt, call); + gsi_replace (gsi, new_stmt, false); + return true; + } + return false; +} + +/* Try to fold IFN_MASK_STORE call CALL. Return true on success. */ + +static bool +gimple_fold_mask_store (gimple_stmt_iterator *gsi, gcall *call) +{ + tree rhs = gimple_call_arg (call, 3); + if (tree lhs = gimple_fold_mask_load_store_mem_ref (call, TREE_TYPE (rhs))) + { + gassign *new_stmt = gimple_build_assign (lhs, rhs); + gimple_set_location (new_stmt, gimple_location (call)); + gimple_move_vops (new_stmt, call); + gsi_replace (gsi, new_stmt, false); + return true; + } + return false; +} + /* Attempt to fold a call statement referenced by the statement iterator GSI. The statement may be replaced by another statement, e.g., if the call simplifies to a constant value. Return true if any changes were made. @@ -4409,6 +4466,12 @@ gimple_fold_call (gimple_stmt_iterator *gsi, bool inplace) subcode = MULT_EXPR; cplx_result = true; break; + case IFN_MASK_LOAD: + changed |= gimple_fold_mask_load (gsi, stmt); + break; + case IFN_MASK_STORE: + changed |= gimple_fold_mask_store (gsi, stmt); + break; default: break; } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index ca99dc67f1b..2db452910db 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2019-08-05 Richard Sandiford + + * gcc.target/aarch64/sve/mask_load_1.c: New test. + 2019-08-05 Jozef Lawrynowicz * gcc.target/msp430/pr80993.c: Add cleanup-saved-temps to final diff --git a/gcc/testsuite/gcc.target/aarch64/sve/mask_load_1.c b/gcc/testsuite/gcc.target/aarch64/sve/mask_load_1.c new file mode 100644 index 00000000000..e76d365cb62 --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/sve/mask_load_1.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -ftree-vectorize -msve-vector-bits=256 -fdump-tree-optimized" } */ + +void +f (int *x) +{ + for (int i = 0; i < 8; ++i) + x[i] += 1; +} + +/* { dg-final { scan-tree-dump { = MEM } "optimized" } } */ +/* { dg-final { scan-tree-dump { MEM \[[^]]*\] = } "optimized" } } */