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Enhance AST dump #8
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the review in github is too large to review. It would be ideal for future PR's to split up the work into smaller commits if possible and expand on your commit message a little bit more. I am extremely guilty of this but its a habit i want to get out of. Can you supply an example rust program your resting with as part of creating the review. Off topic: I will review this properly locally tomorrow still working on a PR to do some static analysis work which i will ask both of you to review also. |
@philberty I'm sorry but this PR is special since it mixed with the indentation fix. I understand they should be separated, but this work is before the topic of the indentation standard discussion. My idea is to merge it then fix the rest indentation with another PR, then we can start the better cooperation for code review. I think it's the cost for us in the very beginning cooperation. What do you think? |
Ah ok yeah that makes sense if this includes some of the indentation fix do you want to add in the rest of the indentation fix into this PR and we can merge it so its done or do you want to get this out of the way first? |
@philberty The AST dump is not complete yet, but the mixed indentation issue may affect other contributors to make new things. So my idea is to merge it ASAP, and I'll raise a new PR for indentation ASAP. Then the world is back to normal. Alas... ;-) |
cool beans i merged it now :) |
This patch adds new movmisalign<mode>_mve_load and store patterns for MVE to help vectorization. They are very similar to their Neon counterparts, but use different iterators and instructions. Indeed MVE supports less vectors modes than Neon, so we use the MVE_VLD_ST iterator where Neon uses VQX. Since the supported modes are different from the ones valid for arithmetic operators, we introduce two new sets of macros: ARM_HAVE_NEON_<MODE>_LDST true if Neon has vector load/store instructions for <MODE> ARM_HAVE_<MODE>_LDST true if any vector extension has vector load/store instructions for <MODE> We move the movmisalign<mode> expander from neon.md to vec-commond.md, and replace the TARGET_NEON enabler with ARM_HAVE_<MODE>_LDST. The patch also updates the mve-vneg.c test to scan for the better code generation when loading and storing the vectors involved: it checks that no 'orr' instruction is generated to cope with misalignment at runtime. This test was chosen among the other mve tests, but any other should be OK. Using a plain vector copy loop (dest[i] = a[i]) is not a good test because the compiler chooses to use memcpy. For instance we now generate: test_vneg_s32x4: vldrw.32 q3, [r1] vneg.s32 q3, q3 vstrw.32 q3, [r0] bx lr instead of: test_vneg_s32x4: orr r3, r1, r0 lsls r3, r3, #28 bne .L15 vldrw.32 q3, [r1] vneg.s32 q3, q3 vstrw.32 q3, [r0] bx lr .L15: push {r4, r5} ldrd r2, r3, [r1, #8] ldrd r5, r4, [r1] rsbs r2, r2, #0 rsbs r5, r5, #0 rsbs r4, r4, #0 rsbs r3, r3, #0 strd r5, r4, [r0] pop {r4, r5} strd r2, r3, [r0, #8] bx lr 2021-01-12 Christophe Lyon <christophe.lyon@linaro.org> PR target/97875 gcc/ * config/arm/arm.h (ARM_HAVE_NEON_V8QI_LDST): New macro. (ARM_HAVE_NEON_V16QI_LDST, ARM_HAVE_NEON_V4HI_LDST): Likewise. (ARM_HAVE_NEON_V8HI_LDST, ARM_HAVE_NEON_V2SI_LDST): Likewise. (ARM_HAVE_NEON_V4SI_LDST, ARM_HAVE_NEON_V4HF_LDST): Likewise. (ARM_HAVE_NEON_V8HF_LDST, ARM_HAVE_NEON_V4BF_LDST): Likewise. (ARM_HAVE_NEON_V8BF_LDST, ARM_HAVE_NEON_V2SF_LDST): Likewise. (ARM_HAVE_NEON_V4SF_LDST, ARM_HAVE_NEON_DI_LDST): Likewise. (ARM_HAVE_NEON_V2DI_LDST): Likewise. (ARM_HAVE_V8QI_LDST, ARM_HAVE_V16QI_LDST): Likewise. (ARM_HAVE_V4HI_LDST, ARM_HAVE_V8HI_LDST): Likewise. (ARM_HAVE_V2SI_LDST, ARM_HAVE_V4SI_LDST, ARM_HAVE_V4HF_LDST): Likewise. (ARM_HAVE_V8HF_LDST, ARM_HAVE_V4BF_LDST, ARM_HAVE_V8BF_LDST): Likewise. (ARM_HAVE_V2SF_LDST, ARM_HAVE_V4SF_LDST, ARM_HAVE_DI_LDST): Likewise. (ARM_HAVE_V2DI_LDST): Likewise. * config/arm/mve.md (*movmisalign<mode>_mve_store): New pattern. (*movmisalign<mode>_mve_load): New pattern. * config/arm/neon.md (movmisalign<mode>): Move to ... * config/arm/vec-common.md: ... here. PR target/97875 gcc/testsuite/ * gcc.target/arm/simd/mve-vneg.c: Update test.
The current restriction on folding memcpy to a single element of size MOVE_MAX is excessively cautious on most machines and limits some significant further optimizations. So relax the restriction provided the copy size does not exceed MOVE_MAX * MOVE_RATIO and that a SET insn exists for moving the value into machine registers. Note that there were already checks in place for having misaligned move operations when one or more of the operands were unaligned. On Arm this now permits optimizing uint64_t bar64(const uint8_t *rData1) { uint64_t buffer; memcpy(&buffer, rData1, sizeof(buffer)); return buffer; } from ldr r2, [r0] @ unaligned sub sp, sp, #8 ldr r3, [r0, #4] @ unaligned strd r2, [sp] ldrd r0, [sp] add sp, sp, #8 to mov r3, r0 ldr r0, [r0] @ unaligned ldr r1, [r3, #4] @ unaligned PR target/102125 - (ARM Cortex-M3 and newer) missed optimization. memcpy not needed operations gcc/ChangeLog: PR target/102125 * gimple-fold.c (gimple_fold_builtin_memory_op): Allow folding memcpy if the size is not more than MOVE_MAX * MOVE_RATIO.
…imize or target pragmas [PR103012] The following testcases ICE when an optimize or target pragma is followed by a long line (4096+ chars). This is because on such long lines we can't use columns anymore, but the cpp_define calls performed by c_cpp_builtins_optimize_pragma or from the backend hooks for target pragma are done on temporary buffers and expect to get columns from whatever line they appear on (which happens to be the long line after optimize/target pragma), and we run into: #0 fancy_abort (file=0x3abec67 "../../libcpp/line-map.c", line=502, function=0x3abecfc "linemap_add") at ../../gcc/diagnostic.c:1986 #1 0x0000000002e7c335 in linemap_add (set=0x7ffff7fca000, reason=LC_RENAME, sysp=0, to_file=0x41287a0 "pr103012.i", to_line=3) at ../../libcpp/line-map.c:502 #2 0x0000000002e7cc24 in linemap_line_start (set=0x7ffff7fca000, to_line=3, max_column_hint=128) at ../../libcpp/line-map.c:827 #3 0x0000000002e7ce2b in linemap_position_for_column (set=0x7ffff7fca000, to_column=1) at ../../libcpp/line-map.c:898 #4 0x0000000002e771f9 in _cpp_lex_direct (pfile=0x40c3b60) at ../../libcpp/lex.c:3592 #5 0x0000000002e76c3e in _cpp_lex_token (pfile=0x40c3b60) at ../../libcpp/lex.c:3394 #6 0x0000000002e610ef in lex_macro_node (pfile=0x40c3b60, is_def_or_undef=true) at ../../libcpp/directives.c:601 #7 0x0000000002e61226 in do_define (pfile=0x40c3b60) at ../../libcpp/directives.c:639 #8 0x0000000002e610b2 in run_directive (pfile=0x40c3b60, dir_no=0, buf=0x7fffffffd430 "__OPTIMIZE__ 1\n", count=14) at ../../libcpp/directives.c:589 #9 0x0000000002e650c1 in cpp_define (pfile=0x40c3b60, str=0x2f784d1 "__OPTIMIZE__") at ../../libcpp/directives.c:2513 #10 0x0000000002e65100 in cpp_define_unused (pfile=0x40c3b60, str=0x2f784d1 "__OPTIMIZE__") at ../../libcpp/directives.c:2522 #11 0x0000000000f50685 in c_cpp_builtins_optimize_pragma (pfile=0x40c3b60, prev_tree=<optimization_node 0x7fffea042000>, cur_tree=<optimization_node 0x7fffea042020>) at ../../gcc/c-family/c-cppbuiltin.c:600 assertion that LC_RENAME doesn't happen first. I think the right fix is emit those predefined macros upon optimize/target pragmas with BUILTINS_LOCATION, like we already do for those macros at the start of the TU, they don't appear in columns of the next line after it. Another possibility would be to force them at the location of the pragma. 2021-12-30 Jakub Jelinek <jakub@redhat.com> PR c++/103012 gcc/ * config/i386/i386-c.c (ix86_pragma_target_parse): Perform cpp_define/cpp_undef calls with forced token locations BUILTINS_LOCATION. * config/arm/arm-c.c (arm_pragma_target_parse): Likewise. * config/aarch64/aarch64-c.c (aarch64_pragma_target_parse): Likewise. * config/s390/s390-c.c (s390_pragma_target_parse): Likewise. gcc/c-family/ * c-cppbuiltin.c (c_cpp_builtins_optimize_pragma): Perform cpp_define_unused/cpp_undef calls with forced token locations BUILTINS_LOCATION. gcc/testsuite/ PR c++/103012 * g++.dg/cpp/pr103012.C: New test. * g++.target/i386/pr103012.C: New test.
This patch extends the fix for PR106253 to AArch32. As with AArch64, we were using ACLE intrinsics to vectorise scalar built-ins, even though the two sometimes have different ECF_* flags. (That in turn is because the ACLE intrinsics should follow the instruction semantics as closely as possible, whereas the scalar built-ins follow language specs.) The patch also removes the copysignf built-in, which only existed for this purpose and wasn't a “real” arm_neon.h built-in. Doing this also has the side-effect of enabling vectorisation of rint and roundeven. Logically that should be a separate patch, but making it one would have meant adding a new int iterator for the original set of instructions and then removing it again when including new functions. I've restricted the bswap tests to little-endian because we end up with excessive spilling on big-endian. E.g.: sub sp, sp, #8 vstr d1, [sp] vldr d16, [sp] vrev16.8 d16, d16 vstr d16, [sp] vldr d0, [sp] add sp, sp, #8 @ sp needed bx lr Similarly, the copysign tests require little-endian because on big-endian we unnecessarily load the constant from the constant pool: vldr.32 s15, .L3 vdup.32 d0, d7[1] vbsl d0, d2, d1 bx lr .L3: .word -2147483648 gcc/ PR target/106253 * config/arm/arm-builtins.cc (arm_builtin_vectorized_function): Delete. * config/arm/arm-protos.h (arm_builtin_vectorized_function): Delete. * config/arm/arm.cc (TARGET_VECTORIZE_BUILTIN_VECTORIZED_FUNCTION): Delete. * config/arm/arm_neon_builtins.def (copysignf): Delete. * config/arm/iterators.md (nvrint_pattern): New attribute. * config/arm/neon.md (<NEON_VRINT:nvrint_pattern><VCVTF:mode>2): New pattern. (l<NEON_VCVT:nvrint_pattern><su_optab><VCVTF:mode><v_cmp_result>2): Likewise. (neon_copysignf<mode>): Rename to... (copysign<mode>3): ...this. gcc/testsuite/ PR target/106253 * gcc.target/arm/vect_unary_1.c: New test. * gcc.target/arm/vect_binary_1.c: Likewise.
Currently SLP tries to force permute operations "down" the graph from loads in the hope of reducing the total number of permutations needed or (in the best case) removing the need for the permutations entirely. This patch tries to extend it as follows: - Allow loads to take a different permutation from the one they started with, rather than choosing between "original permutation" and "no permutation". - Allow changes in both directions, if the target supports the reverse permutation. - Treat the placement of permutations as a two-way dataflow problem: after propagating information from leaves to roots (as now), propagate information back up the graph. - Take execution frequency into account when optimising for speed, so that (for example) permutations inside loops have a higher cost than permutations outside loops. - Try to reduce the total number of permutations when optimising for size, even if that increases the number of permutations on a given execution path. See the big block comment above vect_optimize_slp_pass for a detailed description. The original motivation for doing this was to add a framework that would allow other layout differences in future. The two main ones are: - Make it easier to represent predicated operations, including predicated operations with gaps. E.g.: a[0] += 1; a[1] += 1; a[3] += 1; could be a single load/add/store for SVE. We could handle this by representing a layout such as { 0, 1, _, 2 } or { 0, 1, _, 3 } (depending on what's being counted). We might need to move elements between lanes at various points, like with permutes. (This would first mean adding support for stores with gaps.) - Make it easier to switch between an even/odd and unpermuted layout when switching between wide and narrow elements. E.g. if a widening operation produces an even vector and an odd vector, we should try to keep operations on the wide elements in that order rather than force them to be permuted back "in order". To give some examples of what the patch does: int f1(int *__restrict a, int *__restrict b, int *__restrict c, int *__restrict d) { a[0] = (b[1] << c[3]) - d[1]; a[1] = (b[0] << c[2]) - d[0]; a[2] = (b[3] << c[1]) - d[3]; a[3] = (b[2] << c[0]) - d[2]; } continues to produce the same code as before when optimising for speed: b, c and d are permuted at load time. But when optimising for size we instead permute c into the same order as b+d and then permute the result of the arithmetic into the same order as a: ldr q1, [x2] ldr q0, [x1] ext v1.16b, v1.16b, v1.16b, Rust-GCC#8 // <------ sshl v0.4s, v0.4s, v1.4s ldr q1, [x3] sub v0.4s, v0.4s, v1.4s rev64 v0.4s, v0.4s // <------ str q0, [x0] ret The following function: int f2(int *__restrict a, int *__restrict b, int *__restrict c, int *__restrict d) { a[0] = (b[3] << c[3]) - d[3]; a[1] = (b[2] << c[2]) - d[2]; a[2] = (b[1] << c[1]) - d[1]; a[3] = (b[0] << c[0]) - d[0]; } continues to push the reverse down to just before the store, like the previous code did. In: int f3(int *__restrict a, int *__restrict b, int *__restrict c, int *__restrict d) { for (int i = 0; i < 100; ++i) { a[0] = (a[0] + c[3]); a[1] = (a[1] + c[2]); a[2] = (a[2] + c[1]); a[3] = (a[3] + c[0]); c += 4; } } the loads of a are hoisted and the stores of a are sunk, so that only the load from c happens in the loop. When optimising for speed, we prefer to have the loop operate on the reversed layout, changing on entry and exit from the loop: mov x3, x0 adrp x0, .LC0 add x1, x2, 1600 ldr q2, [x0, #:lo12:.LC0] ldr q0, [x3] mov v1.16b, v0.16b tbl v0.16b, {v0.16b - v1.16b}, v2.16b // <-------- .p2align 3,,7 .L6: ldr q1, [x2], 16 add v0.4s, v0.4s, v1.4s cmp x2, x1 bne .L6 mov v1.16b, v0.16b adrp x0, .LC0 ldr q2, [x0, #:lo12:.LC0] tbl v0.16b, {v0.16b - v1.16b}, v2.16b // <-------- str q0, [x3] ret Similarly, for the very artificial testcase: int f4(int *__restrict a, int *__restrict b, int *__restrict c, int *__restrict d) { int a0 = a[0]; int a1 = a[1]; int a2 = a[2]; int a3 = a[3]; for (int i = 0; i < 100; ++i) { a0 ^= c[0]; a1 ^= c[1]; a2 ^= c[2]; a3 ^= c[3]; c += 4; for (int j = 0; j < 100; ++j) { a0 += d[1]; a1 += d[0]; a2 += d[3]; a3 += d[2]; d += 4; } b[0] = a0; b[1] = a1; b[2] = a2; b[3] = a3; b += 4; } a[0] = a0; a[1] = a1; a[2] = a2; a[3] = a3; } the a vector in the inner loop maintains the order { 1, 0, 3, 2 }, even though it's part of an SCC that includes the outer loop. In other words, this is a motivating case for not assigning permutes at SCC granularity. The code we get is: ldr q0, [x0] mov x4, x1 mov x5, x0 add x1, x3, 1600 add x3, x4, 1600 .p2align 3,,7 .L11: ldr q1, [x2], 16 sub x0, x1, Rust-GCC#1600 eor v0.16b, v1.16b, v0.16b rev64 v0.4s, v0.4s // <--- .p2align 3,,7 .L10: ldr q1, [x0], 16 add v0.4s, v0.4s, v1.4s cmp x0, x1 bne .L10 rev64 v0.4s, v0.4s // <--- add x1, x0, 1600 str q0, [x4], 16 cmp x3, x4 bne .L11 str q0, [x5] ret bb-slp-layout-17.c is a collection of compile tests for problems I hit with earlier versions of the patch. The same prolems might show up elsewhere, but it seemed worth having the test anyway. In slp-11b.c we previously pushed the permutation of the in[i*4] group down from the load to just before the store. That didn't reduce the number or frequency of the permutations (or increase them either). But separating the permute from the load meant that we could no longer use load/store lanes. Whether load/store lanes are a good idea here is another question. If there were two sets of loads, and if we could use a single permutation instead of one per load, then avoiding load/store lanes should be a good thing even under the current abstract cost model. But I think under the current model we should try to avoid splitting up potential load/store lanes groups if there is no specific benefit to the split. Preferring load/store lanes is still a source of missed optimisations that we should fix one day... gcc/ * params.opt (-param=vect-max-layout-candidates=): New parameter. * doc/invoke.texi (vect-max-layout-candidates): Document it. * tree-vectorizer.h (auto_lane_permutation_t): New typedef. (auto_load_permutation_t): Likewise. * tree-vect-slp.cc (vect_slp_node_weight): New function. (slpg_layout_cost): New class. (slpg_vertex): Replace perm_in and perm_out with partition, out_degree, weight and out_weight. (slpg_partition_info, slpg_partition_layout_costs): New classes. (vect_optimize_slp_pass): Likewise, cannibalizing some part of the previous vect_optimize_slp. (vect_optimize_slp): Use it. gcc/testsuite/ * lib/target-supports.exp (check_effective_target_vect_var_shift): Return true for aarch64. * gcc.dg/vect/bb-slp-layout-1.c: New test. * gcc.dg/vect/bb-slp-layout-2.c: New test. * gcc.dg/vect/bb-slp-layout-3.c: New test. * gcc.dg/vect/bb-slp-layout-4.c: New test. * gcc.dg/vect/bb-slp-layout-5.c: New test. * gcc.dg/vect/bb-slp-layout-6.c: New test. * gcc.dg/vect/bb-slp-layout-7.c: New test. * gcc.dg/vect/bb-slp-layout-8.c: New test. * gcc.dg/vect/bb-slp-layout-9.c: New test. * gcc.dg/vect/bb-slp-layout-10.c: New test. * gcc.dg/vect/bb-slp-layout-11.c: New test. * gcc.dg/vect/bb-slp-layout-13.c: New test. * gcc.dg/vect/bb-slp-layout-14.c: New test. * gcc.dg/vect/bb-slp-layout-15.c: New test. * gcc.dg/vect/bb-slp-layout-16.c: New test. * gcc.dg/vect/bb-slp-layout-17.c: New test. * gcc.dg/vect/slp-11b.c: XFAIL SLP test for load-lanes targets.
Currently SLP tries to force permute operations "down" the graph from loads in the hope of reducing the total number of permutations needed or (in the best case) removing the need for the permutations entirely. This patch tries to extend it as follows: - Allow loads to take a different permutation from the one they started with, rather than choosing between "original permutation" and "no permutation". - Allow changes in both directions, if the target supports the reverse permutation. - Treat the placement of permutations as a two-way dataflow problem: after propagating information from leaves to roots (as now), propagate information back up the graph. - Take execution frequency into account when optimising for speed, so that (for example) permutations inside loops have a higher cost than permutations outside loops. - Try to reduce the total number of permutations when optimising for size, even if that increases the number of permutations on a given execution path. See the big block comment above vect_optimize_slp_pass for a detailed description. The original motivation for doing this was to add a framework that would allow other layout differences in future. The two main ones are: - Make it easier to represent predicated operations, including predicated operations with gaps. E.g.: a[0] += 1; a[1] += 1; a[3] += 1; could be a single load/add/store for SVE. We could handle this by representing a layout such as { 0, 1, _, 2 } or { 0, 1, _, 3 } (depending on what's being counted). We might need to move elements between lanes at various points, like with permutes. (This would first mean adding support for stores with gaps.) - Make it easier to switch between an even/odd and unpermuted layout when switching between wide and narrow elements. E.g. if a widening operation produces an even vector and an odd vector, we should try to keep operations on the wide elements in that order rather than force them to be permuted back "in order". To give some examples of what the patch does: int f1(int *__restrict a, int *__restrict b, int *__restrict c, int *__restrict d) { a[0] = (b[1] << c[3]) - d[1]; a[1] = (b[0] << c[2]) - d[0]; a[2] = (b[3] << c[1]) - d[3]; a[3] = (b[2] << c[0]) - d[2]; } continues to produce the same code as before when optimising for speed: b, c and d are permuted at load time. But when optimising for size we instead permute c into the same order as b+d and then permute the result of the arithmetic into the same order as a: ldr q1, [x2] ldr q0, [x1] ext v1.16b, v1.16b, v1.16b, #8 // <------ sshl v0.4s, v0.4s, v1.4s ldr q1, [x3] sub v0.4s, v0.4s, v1.4s rev64 v0.4s, v0.4s // <------ str q0, [x0] ret The following function: int f2(int *__restrict a, int *__restrict b, int *__restrict c, int *__restrict d) { a[0] = (b[3] << c[3]) - d[3]; a[1] = (b[2] << c[2]) - d[2]; a[2] = (b[1] << c[1]) - d[1]; a[3] = (b[0] << c[0]) - d[0]; } continues to push the reverse down to just before the store, like the previous code did. In: int f3(int *__restrict a, int *__restrict b, int *__restrict c, int *__restrict d) { for (int i = 0; i < 100; ++i) { a[0] = (a[0] + c[3]); a[1] = (a[1] + c[2]); a[2] = (a[2] + c[1]); a[3] = (a[3] + c[0]); c += 4; } } the loads of a are hoisted and the stores of a are sunk, so that only the load from c happens in the loop. When optimising for speed, we prefer to have the loop operate on the reversed layout, changing on entry and exit from the loop: mov x3, x0 adrp x0, .LC0 add x1, x2, 1600 ldr q2, [x0, #:lo12:.LC0] ldr q0, [x3] mov v1.16b, v0.16b tbl v0.16b, {v0.16b - v1.16b}, v2.16b // <-------- .p2align 3,,7 .L6: ldr q1, [x2], 16 add v0.4s, v0.4s, v1.4s cmp x2, x1 bne .L6 mov v1.16b, v0.16b adrp x0, .LC0 ldr q2, [x0, #:lo12:.LC0] tbl v0.16b, {v0.16b - v1.16b}, v2.16b // <-------- str q0, [x3] ret Similarly, for the very artificial testcase: int f4(int *__restrict a, int *__restrict b, int *__restrict c, int *__restrict d) { int a0 = a[0]; int a1 = a[1]; int a2 = a[2]; int a3 = a[3]; for (int i = 0; i < 100; ++i) { a0 ^= c[0]; a1 ^= c[1]; a2 ^= c[2]; a3 ^= c[3]; c += 4; for (int j = 0; j < 100; ++j) { a0 += d[1]; a1 += d[0]; a2 += d[3]; a3 += d[2]; d += 4; } b[0] = a0; b[1] = a1; b[2] = a2; b[3] = a3; b += 4; } a[0] = a0; a[1] = a1; a[2] = a2; a[3] = a3; } the a vector in the inner loop maintains the order { 1, 0, 3, 2 }, even though it's part of an SCC that includes the outer loop. In other words, this is a motivating case for not assigning permutes at SCC granularity. The code we get is: ldr q0, [x0] mov x4, x1 mov x5, x0 add x1, x3, 1600 add x3, x4, 1600 .p2align 3,,7 .L11: ldr q1, [x2], 16 sub x0, x1, Rust-GCC#1600 eor v0.16b, v1.16b, v0.16b rev64 v0.4s, v0.4s // <--- .p2align 3,,7 .L10: ldr q1, [x0], 16 add v0.4s, v0.4s, v1.4s cmp x0, x1 bne .L10 rev64 v0.4s, v0.4s // <--- add x1, x0, 1600 str q0, [x4], 16 cmp x3, x4 bne .L11 str q0, [x5] ret bb-slp-layout-17.c is a collection of compile tests for problems I hit with earlier versions of the patch. The same prolems might show up elsewhere, but it seemed worth having the test anyway. In slp-11b.c we previously pushed the permutation of the in[i*4] group down from the load to just before the store. That didn't reduce the number or frequency of the permutations (or increase them either). But separating the permute from the load meant that we could no longer use load/store lanes. Whether load/store lanes are a good idea here is another question. If there were two sets of loads, and if we could use a single permutation instead of one per load, then avoiding load/store lanes should be a good thing even under the current abstract cost model. But I think under the current model we should try to avoid splitting up potential load/store lanes groups if there is no specific benefit to the split. Preferring load/store lanes is still a source of missed optimisations that we should fix one day... gcc/ * params.opt (-param=vect-max-layout-candidates=): New parameter. * doc/invoke.texi (vect-max-layout-candidates): Document it. * tree-vectorizer.h (auto_lane_permutation_t): New typedef. (auto_load_permutation_t): Likewise. * tree-vect-slp.cc (vect_slp_node_weight): New function. (slpg_layout_cost): New class. (slpg_vertex): Replace perm_in and perm_out with partition, out_degree, weight and out_weight. (slpg_partition_info, slpg_partition_layout_costs): New classes. (vect_optimize_slp_pass): Likewise, cannibalizing some part of the previous vect_optimize_slp. (vect_optimize_slp): Use it. gcc/testsuite/ * lib/target-supports.exp (check_effective_target_vect_var_shift): Return true for aarch64. * gcc.dg/vect/bb-slp-layout-1.c: New test. * gcc.dg/vect/bb-slp-layout-2.c: New test. * gcc.dg/vect/bb-slp-layout-3.c: New test. * gcc.dg/vect/bb-slp-layout-4.c: New test. * gcc.dg/vect/bb-slp-layout-5.c: New test. * gcc.dg/vect/bb-slp-layout-6.c: New test. * gcc.dg/vect/bb-slp-layout-7.c: New test. * gcc.dg/vect/bb-slp-layout-8.c: New test. * gcc.dg/vect/bb-slp-layout-9.c: New test. * gcc.dg/vect/bb-slp-layout-10.c: New test. * gcc.dg/vect/bb-slp-layout-11.c: New test. * gcc.dg/vect/bb-slp-layout-13.c: New test. * gcc.dg/vect/bb-slp-layout-14.c: New test. * gcc.dg/vect/bb-slp-layout-15.c: New test. * gcc.dg/vect/bb-slp-layout-16.c: New test. * gcc.dg/vect/bb-slp-layout-17.c: New test. * gcc.dg/vect/slp-11b.c: XFAIL SLP test for load-lanes targets.
The aarch64 ISA specification allows a left shift amount to be applied after extension in the range of 0 to 4 (encoded in the imm3 field). This is true for at least the following instructions: * ADD (extend register) * ADDS (extended register) * SUB (extended register) The result of this patch can be seen, when compiling the following code: uint64_t myadd(uint64_t a, uint64_t b) { return a+(((uint8_t)b)<<4); } Without the patch the following sequence will be generated: 0000000000000000 <myadd>: 0: d37c1c21 ubfiz x1, x1, #4, #8 4: 8b000020 add x0, x1, x0 8: d65f03c0 ret With the patch the ubfiz will be merged into the add instruction: 0000000000000000 <myadd>: 0: 8b211000 add x0, x0, w1, uxtb #4 4: d65f03c0 ret gcc/ChangeLog: * config/aarch64/aarch64.cc (aarch64_uxt_size): fix an off-by-one in checking the permissible shift-amount.
…hook [PR108583] This replaces the custom division hook with just an implementation through add_highpart. For NEON we implement the add highpart (Addition + extraction of the upper highpart of the register in the same precision) as ADD + LSR. This representation allows us to easily optimize the sequence using existing sequences. This gets us a pretty decent sequence using SRA: umull v1.8h, v0.8b, v3.8b umull2 v0.8h, v0.16b, v3.16b add v5.8h, v1.8h, v2.8h add v4.8h, v0.8h, v2.8h usra v1.8h, v5.8h, 8 usra v0.8h, v4.8h, 8 uzp2 v1.16b, v1.16b, v0.16b To get the most optimal sequence however we match (a + ((b + c) >> n)) where n is half the precision of the mode of the operation into addhn + uaddw which is a general good optimization on its own and gets us back to: .L4: ldr q0, [x3] umull v1.8h, v0.8b, v5.8b umull2 v0.8h, v0.16b, v5.16b addhn v3.8b, v1.8h, v4.8h addhn v2.8b, v0.8h, v4.8h uaddw v1.8h, v1.8h, v3.8b uaddw v0.8h, v0.8h, v2.8b uzp2 v1.16b, v1.16b, v0.16b str q1, [x3], 16 cmp x3, x4 bne .L4 For SVE2 we optimize the initial sequence to the same ADD + LSR which gets us: .L3: ld1b z0.h, p0/z, [x0, x3] mul z0.h, p1/m, z0.h, z2.h add z1.h, z0.h, z3.h usra z0.h, z1.h, #8 lsr z0.h, z0.h, #8 st1b z0.h, p0, [x0, x3] inch x3 whilelo p0.h, w3, w2 b.any .L3 .L1: ret and to get the most optimal sequence I match (a + b) >> n (same constraint on n) to addhnb which gets us to: .L3: ld1b z0.h, p0/z, [x0, x3] mul z0.h, p1/m, z0.h, z2.h addhnb z1.b, z0.h, z3.h addhnb z0.b, z0.h, z1.h st1b z0.h, p0, [x0, x3] inch x3 whilelo p0.h, w3, w2 b.any .L3 There are multiple RTL representations possible for these optimizations, I did not represent them using a zero_extend because we seem very inconsistent in this in the backend. Since they are unspecs we won't match them from vector ops anyway. I figured maintainers would prefer this, but my maintainer ouija board is still out for repairs :) There are no new test as new correctness tests were added to the mid-end and the existing codegen tests for this already exist. gcc/ChangeLog: PR target/108583 * config/aarch64/aarch64-simd.md (@aarch64_bitmask_udiv<mode>3): Remove. (*bitmask_shift_plus<mode>): New. * config/aarch64/aarch64-sve2.md (*bitmask_shift_plus<mode>): New. (@aarch64_bitmask_udiv<mode>3): Remove. * config/aarch64/aarch64.cc (aarch64_vectorize_can_special_div_by_constant, TARGET_VECTORIZE_CAN_SPECIAL_DIV_BY_CONST): Removed. (TARGET_VECTORIZE_PREFERRED_DIV_AS_SHIFTS_OVER_MULT, aarch64_vectorize_preferred_div_as_shifts_over_mult): New.
See #7