From: Martin Liska Date: Thu, 2 May 2019 07:57:38 +0000 (+0200) Subject: Prefer to use strlen call instead of inline expansion (PR target/88809). X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=786e0e5239529de9a4254fe8411a0e8f843e721a;p=gcc.git Prefer to use strlen call instead of inline expansion (PR target/88809). 2019-05-02 Martin Liska PR target/88809 * config/i386/i386.c (ix86_expand_strlen): Use strlen call. With -minline-all-stringops use inline expansion using 4B loop. * doc/invoke.texi: Document the change of -minline-all-stringops. 2019-05-02 Martin Liska PR target/88809 * gcc.target/i386/pr88809.c: New test. * gcc.target/i386/pr88809-2.c: New test. From-SVN: r270787 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7f6ccd98c11..1883e4df91f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2019-05-02 Martin Liska + + PR target/88809 + * config/i386/i386.c (ix86_expand_strlen): Use strlen call. + With -minline-all-stringops use inline expansion using 4B loop. + * doc/invoke.texi: Document the change of + -minline-all-stringops. + 2019-05-01 Jeff Law PR tree-optimization/88797 diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 43ee77606e5..e7ee83d6372 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -28270,68 +28270,34 @@ ix86_expand_strlensi_unroll_1 (rtx out, rtx src, rtx align_rtx) bool ix86_expand_strlen (rtx out, rtx src, rtx eoschar, rtx align) { - rtx addr, scratch1, scratch2, scratch3, scratch4; - - /* The generic case of strlen expander is long. Avoid it's - expanding unless TARGET_INLINE_ALL_STRINGOPS. */ - - if (TARGET_UNROLL_STRLEN && eoschar == const0_rtx && optimize > 1 - && !TARGET_INLINE_ALL_STRINGOPS - && !optimize_insn_for_size_p () - && (!CONST_INT_P (align) || INTVAL (align) < 4)) - return false; - - addr = force_reg (Pmode, XEXP (src, 0)); - scratch1 = gen_reg_rtx (Pmode); - - if (TARGET_UNROLL_STRLEN && eoschar == const0_rtx && optimize > 1 - && !optimize_insn_for_size_p ()) - { +if (TARGET_UNROLL_STRLEN + && TARGET_INLINE_ALL_STRINGOPS + && eoschar == const0_rtx + && optimize > 1) + { + /* The generic case of strlen expander is long. Avoid it's + expanding unless TARGET_INLINE_ALL_STRINGOPS. */ + rtx addr = force_reg (Pmode, XEXP (src, 0)); /* Well it seems that some optimizer does not combine a call like - foo(strlen(bar), strlen(bar)); - when the move and the subtraction is done here. It does calculate - the length just once when these instructions are done inside of - output_strlen_unroll(). But I think since &bar[strlen(bar)] is - often used and I use one fewer register for the lifetime of - output_strlen_unroll() this is better. */ + foo(strlen(bar), strlen(bar)); + when the move and the subtraction is done here. It does calculate + the length just once when these instructions are done inside of + output_strlen_unroll(). But I think since &bar[strlen(bar)] is + often used and I use one fewer register for the lifetime of + output_strlen_unroll() this is better. */ emit_move_insn (out, addr); ix86_expand_strlensi_unroll_1 (out, src, align); /* strlensi_unroll_1 returns the address of the zero at the end of - the string, like memchr(), so compute the length by subtracting - the start address. */ + the string, like memchr(), so compute the length by subtracting + the start address. */ emit_insn (ix86_gen_sub3 (out, out, addr)); + return true; } else - { - rtx unspec; - - /* Can't use this if the user has appropriated eax, ecx, or edi. */ - if (fixed_regs[AX_REG] || fixed_regs[CX_REG] || fixed_regs[DI_REG]) - return false; - /* Can't use this for non-default address spaces. */ - if (!ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (src))) - return false; - - scratch2 = gen_reg_rtx (Pmode); - scratch3 = gen_reg_rtx (Pmode); - scratch4 = force_reg (Pmode, constm1_rtx); - - emit_move_insn (scratch3, addr); - eoschar = force_reg (QImode, eoschar); - - src = replace_equiv_address_nv (src, scratch3); - - /* If .md starts supporting :P, this can be done in .md. */ - unspec = gen_rtx_UNSPEC (Pmode, gen_rtvec (4, src, eoschar, align, - scratch4), UNSPEC_SCAS); - emit_insn (gen_strlenqi_1 (scratch1, scratch3, unspec)); - emit_insn (ix86_gen_one_cmpl2 (scratch2, scratch1)); - emit_insn (ix86_gen_add3 (out, scratch2, constm1_rtx)); - } - return true; + return false; } /* For given symbol (function) construct code to compute address of it's PLT diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 516eb24eb74..de7e1aaec67 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -28506,8 +28506,9 @@ By default GCC inlines string operations only when the destination is known to be aligned to least a 4-byte boundary. This enables more inlining and increases code size, but may improve performance of code that depends on fast -@code{memcpy}, @code{strlen}, -and @code{memset} for short lengths. +@code{memcpy} and @code{memset} for short lengths. +The option enables inline expansion of @code{strlen} for all +pointer alignments. @item -minline-stringops-dynamically @opindex minline-stringops-dynamically diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 45b181a24f8..30227ca83b6 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2019-05-02 Martin Liska + + PR target/88809 + * gcc.target/i386/pr88809.c: New test. + * gcc.target/i386/pr88809-2.c: New test. + 2019-05-01 Dominique d'Humieres PR fortran/60144 diff --git a/gcc/testsuite/gcc.target/i386/pr88809-2.c b/gcc/testsuite/gcc.target/i386/pr88809-2.c new file mode 100644 index 00000000000..b8ef51dab5b --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr88809-2.c @@ -0,0 +1,9 @@ +/* PR target/88809 */ +/* { dg-options "-Os" } */ + +unsigned int foo (const char *ptr) +{ + return __builtin_strlen (ptr); +} + +/* { dg-final { scan-assembler "call\[ \t\]strlen" } } */ diff --git a/gcc/testsuite/gcc.target/i386/pr88809.c b/gcc/testsuite/gcc.target/i386/pr88809.c new file mode 100644 index 00000000000..20844ddb921 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr88809.c @@ -0,0 +1,9 @@ +/* PR target/88809 */ +/* { dg-options "-O" } */ + +unsigned int foo (const char *ptr) +{ + return __builtin_strlen (ptr); +} + +/* { dg-final { scan-assembler "call\[ \t\]strlen" } } */