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On 03/10/23 3:53 pm, Surya Kumari Jangala wrote: > Ping > > On 20/09/23 7:31 am, Surya Kumari Jangala wrote: >> Ping >> >> On 10/09/23 10:58 pm, Surya Kumari Jangala wrote: >>> swap: Fix incorrect lane extraction by vec_extract() [PR106770] >>> >>> In the routine rs6000_analyze_swaps(), special handling of swappable >>> instructions is done even if the webs that contain the swappable >>> instructions are not optimized, i.e., the webs do not contain any >>> permuting load/store instructions along with the associated register >>> swap instructions. Doing special handling in such webs will result in >>> the extracted lane being adjusted unnecessarily for vec_extract. >>> >>> Another issue is that existing code treats non-permuting loads/stores >>> as special swappables. Non-permuting loads/stores (that have not yet >>> been split into a permuting load/store and a swap) are handled by >>> converting them into a permuting load/store (which effectively removes >>> the swap). As a result, if special swappables are handled only in webs >>> containing permuting loads/stores, then non-optimal code is generated >>> for non-permuting loads/stores. >>> >>> Hence, in this patch, all webs containing either permuting loads/ >>> stores or non-permuting loads/stores are marked as requiring special >>> handling of swappables. Swaps associated with permuting loads/stores >>> are marked for removal, and non-permuting loads/stores are converted to >>> permuting loads/stores. Then the special swappables in the webs are >>> fixed up. >>> >>> Another issue with always handling swappable instructions is that it is >>> incorrect to do so in webs where loads/stores on quad word aligned >>> addresses are changed to lvx/stvx. Similarly, in webs where >>> swap(load(vector constant)) instructions are replaced with >>> load(swapped vector constant), the swappable instructions should not be >>> modified. >>> >>> 2023-09-10 Surya Kumari Jangala <jskum...@linux.ibm.com> >>> >>> gcc/ >>> PR rtl-optimization/PR106770 >>> * config/rs6000/rs6000-p8swap.cc (non_permuting_mem_insn): New >>> function. >>> (handle_non_permuting_mem_insn): New function. >>> (rs6000_analyze_swaps): Handle swappable instructions only in >>> certain webs. >>> (web_requires_special_handling): New instance variable. >>> (handle_special_swappables): Remove handling of non-permuting >>> load/store instructions. >>> >>> gcc/testsuite/ >>> PR rtl-optimization/PR106770 >>> * gcc.target/powerpc/pr106770.c: New test. >>> --- >>> >>> diff --git a/gcc/config/rs6000/rs6000-p8swap.cc >>> b/gcc/config/rs6000/rs6000-p8swap.cc >>> index 0388b9bd736..3a695aa1318 100644 >>> --- a/gcc/config/rs6000/rs6000-p8swap.cc >>> +++ b/gcc/config/rs6000/rs6000-p8swap.cc >>> @@ -179,6 +179,13 @@ class swap_web_entry : public web_entry_base >>> unsigned int special_handling : 4; >>> /* Set if the web represented by this entry cannot be optimized. */ >>> unsigned int web_not_optimizable : 1; >>> + /* Set if the swappable insns in the web represented by this entry >>> + have to be fixed. Swappable insns have to be fixed in : >>> + - webs containing permuting loads/stores and the swap insns >>> + in such webs have been marked for removal >>> + - webs where non-permuting loads/stores have been converted >>> + to permuting loads/stores */ >>> + unsigned int web_requires_special_handling : 1; >>> /* Set if this insn should be deleted. */ >>> unsigned int will_delete : 1; >>> }; >>> @@ -1468,14 +1475,6 @@ handle_special_swappables (swap_web_entry >>> *insn_entry, unsigned i) >>> if (dump_file) >>> fprintf (dump_file, "Adjusting subreg in insn %d\n", i); >>> break; >>> - case SH_NOSWAP_LD: >>> - /* Convert a non-permuting load to a permuting one. */ >>> - permute_load (insn); >>> - break; >>> - case SH_NOSWAP_ST: >>> - /* Convert a non-permuting store to a permuting one. */ >>> - permute_store (insn); >>> - break; >>> case SH_EXTRACT: >>> /* Change the lane on an extract operation. */ >>> adjust_extract (insn); >>> @@ -2401,6 +2400,25 @@ recombine_lvx_stvx_patterns (function *fun) >>> free (to_delete); >>> } >>> >>> +/* Return true if insn is a non-permuting load/store. */ >>> +static bool >>> +non_permuting_mem_insn (swap_web_entry *insn_entry, unsigned int i) >>> +{ >>> + return (insn_entry[i].special_handling == SH_NOSWAP_LD || >>> + insn_entry[i].special_handling == SH_NOSWAP_ST); >>> +} >>> + >>> +/* Convert a non-permuting load/store insn to a permuting one. */ >>> +static void >>> +handle_non_permuting_mem_insn (swap_web_entry *insn_entry, unsigned int i) >>> +{ >>> + rtx_insn *insn = insn_entry[i].insn; >>> + if (insn_entry[i].special_handling == SH_NOSWAP_LD) >>> + permute_load (insn); >>> + else if (insn_entry[i].special_handling == SH_NOSWAP_ST) >>> + permute_store (insn); >>> +} >>> + >>> /* Main entry point for this pass. */ >>> unsigned int >>> rs6000_analyze_swaps (function *fun) >>> @@ -2624,25 +2642,56 @@ rs6000_analyze_swaps (function *fun) >>> dump_swap_insn_table (insn_entry); >>> } >>> >>> - /* For each load and store in an optimizable web (which implies >>> - the loads and stores are permuting), find the associated >>> - register swaps and mark them for removal. Due to various >>> - optimizations we may mark the same swap more than once. Also >>> - perform special handling for swappable insns that require it. */ >>> + /* There are two kinds of optimizations that can be performed on an >>> + optimizable web: >>> + 1. Remove the register swaps associated with permuting load/store >>> + in an optimizable web >>> + 2. Convert the vanilla loads/stores (that have not yet been split >>> + into a permuting load/store and a swap) into a permuting >>> + load/store (which effectively removes the swap) >>> + In both the cases, swappable instructions in the webs need >>> + special handling to fix them up. */ >>> for (i = 0; i < e; ++i) >>> + /* For each permuting load/store in an optimizable web, find >>> + the associated register swaps and mark them for removal. >>> + Due to various optimizations we may mark the same swap more >>> + than once. */ >>> if ((insn_entry[i].is_load || insn_entry[i].is_store) >>> && insn_entry[i].is_swap) >>> { >>> swap_web_entry* root_entry >>> = (swap_web_entry*)((&insn_entry[i])->unionfind_root ()); >>> if (!root_entry->web_not_optimizable) >>> - mark_swaps_for_removal (insn_entry, i); >>> + { >>> + mark_swaps_for_removal (insn_entry, i); >>> + root_entry->web_requires_special_handling = true; >>> + } >>> } >>> - else if (insn_entry[i].is_swappable && insn_entry[i].special_handling) >>> + /* Convert the non-permuting loads/stores into a permuting >>> + load/store. */ >>> + else if (insn_entry[i].is_swappable >>> + && non_permuting_mem_insn (insn_entry, i)) >>> { >>> swap_web_entry* root_entry >>> = (swap_web_entry*)((&insn_entry[i])->unionfind_root ()); >>> if (!root_entry->web_not_optimizable) >>> + { >>> + handle_non_permuting_mem_insn (insn_entry, i); >>> + root_entry->web_requires_special_handling = true; >>> + } >>> + } >>> + >>> + /* Perform special handling for swappable insns that require it. >>> + Note that special handling should be done only for those >>> + swappable insns that are present in webs marked as requiring >>> + special handling. */ >>> + for (i = 0; i < e; ++i) >>> + if (insn_entry[i].is_swappable && insn_entry[i].special_handling && >>> + !non_permuting_mem_insn (insn_entry, i)) >>> + { >>> + swap_web_entry* root_entry >>> + = (swap_web_entry*)((&insn_entry[i])->unionfind_root ()); >>> + if (root_entry->web_requires_special_handling) >>> handle_special_swappables (insn_entry, i); >>> } >>> >>> diff --git a/gcc/testsuite/gcc.target/powerpc/pr106770.c >>> b/gcc/testsuite/gcc.target/powerpc/pr106770.c >>> new file mode 100644 >>> index 00000000000..11efe39abc5 >>> --- /dev/null >>> +++ b/gcc/testsuite/gcc.target/powerpc/pr106770.c >>> @@ -0,0 +1,21 @@ >>> +/* { dg-do compile } */ >>> +/* { dg-require-effective-target powerpc_p8vector_ok } */ >>> +/* { dg-options "-mdejagnu-cpu=power8 -O2 " } */ >>> +/* The 2 xxpermdi instructions are generated by the two >>> + calls to vec_promote() */ >>> +/* { dg-final { scan-assembler-times "xxpermdi" 2 } } */ >>> + >>> +/* Test case to resolve PR106770 */ >>> + >>> +#include <altivec.h> >>> + >>> +int cmp2(double a, double b) >>> +{ >>> + vector double va = vec_promote(a, 1); >>> + vector double vb = vec_promote(b, 1); >>> + vector long long vlt = (vector long long)vec_cmplt(va, vb); >>> + vector long long vgt = (vector long long)vec_cmplt(vb, va); >>> + vector signed long long vr = vec_sub(vlt, vgt); >>> + >>> + return vec_extract(vr, 1); >>> +} >>>