On Tue, Jun 21, 2016 at 9:51 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
>> I have attached my version of the patch. It handles all your >> testcases, plus &foo+1 case. Bootstrap is still running. >> >> Does the patch work for you? > > It works. Attached version of the patch was committed to mainline SVN. Regarding the testcases - I have made them to compile on non-ia32 only ATM. Let's change them when ia32 support is added (it is a trivial change). 2016-06-23 Uros Bizjak <ubiz...@gmail.com> H.J. Lu <hongjiu...@intel.com> PR target/67400 * config/i386/i386-protos.h (ix86_force_load_from_GOT_p): New. * config/i386/i386.c (ix86_force_load_from_GOT_p): New function. (ix86_legitimate_constant_p): Do not allow UNSPEC_GOTPCREL if ix86_force_load_from_GOT_p returns true. (ix86_legitimate_address_p): Allow UNSPEC_GOTPCREL if ix86_force_load_from_GOT_p returns true. (ix86_print_operand_address_as): Support UNSPEC_GOTPCREL if ix86_force_load_from_GOT_p returns true. (ix86_expand_move): Load the external function address via the GOT slot if ix86_force_load_from_GOT_p returns true. * config/i386/predicates.md (x86_64_immediate_operand): Return false for SYMBOL_REFs where ix86_force_load_from_GOT_p returns true. (x86_64_zext_immediate_operand): Ditto. testsuite/ChangeLog: 2016-06-23 H.J. Lu <hongjiu...@intel.com> PR target/67400 * gcc.target/i386/pr67400-1.c: New test. * gcc.target/i386/pr67400-2.c: Likewise. * gcc.target/i386/pr67400-3.c: Likewise. * gcc.target/i386/pr67400-4.c: Likewise. * gcc.target/i386/pr67400-5.c: Likewise. * gcc.target/i386/pr67400-6.c: Likewise. * gcc.target/i386/pr67400-7.c: Likewise. Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}. Committed to mainline SVN. Uros.
Index: config/i386/i386-protos.h =================================================================== --- config/i386/i386-protos.h (revision 237716) +++ config/i386/i386-protos.h (working copy) @@ -70,6 +70,7 @@ extern bool ix86_expand_set_or_movmem (rtx, rtx, r extern bool constant_address_p (rtx); extern bool legitimate_pic_operand_p (rtx); extern bool legitimate_pic_address_disp_p (rtx); +extern bool ix86_force_load_from_GOT_p (rtx); extern void print_reg (rtx, int, FILE*); extern void ix86_print_operand (FILE *, rtx, int); Index: config/i386/i386.c =================================================================== --- config/i386/i386.c (revision 237716) +++ config/i386/i386.c (working copy) @@ -15120,6 +15120,19 @@ darwin_local_data_pic (rtx disp) && XINT (disp, 1) == UNSPEC_MACHOPIC_OFFSET); } +/* True if operand X should be loaded from GOT. */ + +bool +ix86_force_load_from_GOT_p (rtx x) +{ + return (TARGET_64BIT && !TARGET_PECOFF && !TARGET_MACHO + && !flag_plt && !flag_pic + && ix86_cmodel != CM_LARGE + && GET_CODE (x) == SYMBOL_REF + && SYMBOL_REF_FUNCTION_P (x) + && !SYMBOL_REF_LOCAL_P (x)); +} + /* Determine if a given RTX is a valid constant. We already know this satisfies CONSTANT_P. */ @@ -15188,6 +15201,12 @@ ix86_legitimate_constant_p (machine_mode mode, rtx if (MACHO_DYNAMIC_NO_PIC_P) return machopic_symbol_defined_p (x); #endif + + /* External function address should be loaded + via the GOT slot to avoid PLT. */ + if (ix86_force_load_from_GOT_p (x)) + return false; + break; CASE_CONST_SCALAR_INT: @@ -15596,6 +15615,9 @@ ix86_legitimate_address_p (machine_mode, rtx addr, return false; case UNSPEC_GOTPCREL: + if (ix86_force_load_from_GOT_p (XVECEXP (XEXP (disp, 0), 0, 0))) + goto is_legitimate_pic; + /* FALLTHRU */ case UNSPEC_PCREL: gcc_assert (flag_pic); goto is_legitimate_pic; @@ -18169,6 +18191,12 @@ ix86_print_operand_address_as (FILE *file, rtx add fputs ("ds:", file); fprintf (file, HOST_WIDE_INT_PRINT_DEC, INTVAL (disp)); } + /* Load the external function address via the GOT slot to avoid PLT. */ + else if (GET_CODE (disp) == CONST + && GET_CODE (XEXP (disp, 0)) == UNSPEC + && XINT (XEXP (disp, 0), 1) == UNSPEC_GOTPCREL + && ix86_force_load_from_GOT_p (XVECEXP (XEXP (disp, 0), 0, 0))) + output_pic_addr_const (file, disp, 0); else if (flag_pic) output_pic_addr_const (file, disp, 0); else @@ -19417,6 +19445,15 @@ ix86_expand_move (machine_mode mode, rtx operands[ if (model) op1 = legitimize_tls_address (op1, model, true); + else if (ix86_force_load_from_GOT_p (op1)) + { + /* Load the external function address via GOT slot to avoid PLT. */ + op1 = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, op1), + UNSPEC_GOTPCREL); + op1 = gen_rtx_CONST (Pmode, op1); + op1 = gen_const_mem (Pmode, op1); + set_mem_alias_set (op1, ix86_GOT_alias_set ()); + } else { tmp = legitimize_pe_coff_symbol (op1, addend != NULL_RTX); Index: config/i386/predicates.md =================================================================== --- config/i386/predicates.md (revision 237716) +++ config/i386/predicates.md (working copy) @@ -160,13 +160,18 @@ return trunc_int_for_mode (val, SImode) == val; } case SYMBOL_REF: + /* TLS symbols are not constant. */ + if (SYMBOL_REF_TLS_MODEL (op)) + return false; + + /* Load the external function address via the GOT slot. */ + if (ix86_force_load_from_GOT_p (op)) + return false; + /* For certain code models, the symbolic references are known to fit. in CM_SMALL_PIC model we know it fits if it is local to the shared library. Don't count TLS SYMBOL_REFs here, since they should fit only if inside of UNSPEC handled below. */ - /* TLS symbols are not constant. */ - if (SYMBOL_REF_TLS_MODEL (op)) - return false; return (ix86_cmodel == CM_SMALL || ix86_cmodel == CM_KERNEL || (ix86_cmodel == CM_MEDIUM && !SYMBOL_REF_FAR_ADDR_P (op))); @@ -207,6 +212,11 @@ /* TLS symbols are not constant. */ if (SYMBOL_REF_TLS_MODEL (op1)) return false; + + /* Load the external function address via the GOT slot. */ + if (ix86_force_load_from_GOT_p (op1)) + return false; + /* For CM_SMALL assume that latest object is 16MB before end of 31bits boundary. We may also accept pretty large negative constants knowing that all objects are @@ -273,10 +283,15 @@ return !(INTVAL (op) & ~(HOST_WIDE_INT) 0xffffffff); case SYMBOL_REF: - /* For certain code models, the symbolic references are known to fit. */ /* TLS symbols are not constant. */ if (SYMBOL_REF_TLS_MODEL (op)) return false; + + /* Load the external function address via the GOT slot. */ + if (ix86_force_load_from_GOT_p (op)) + return false; + + /* For certain code models, the symbolic references are known to fit. */ return (ix86_cmodel == CM_SMALL || (ix86_cmodel == CM_MEDIUM && !SYMBOL_REF_FAR_ADDR_P (op))); @@ -301,6 +316,11 @@ /* TLS symbols are not constant. */ if (SYMBOL_REF_TLS_MODEL (op1)) return false; + + /* Load the external function address via the GOT slot. */ + if (ix86_force_load_from_GOT_p (op1)) + return false; + /* For small code model we may accept pretty large positive offsets, since one bit is available for free. Negative offsets are limited by the size of NULL pointer area Index: testsuite/gcc.target/i386/pr67400-1.c =================================================================== --- testsuite/gcc.target/i386/pr67400-1.c (nonexistent) +++ testsuite/gcc.target/i386/pr67400-1.c (working copy) @@ -0,0 +1,13 @@ +/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +extern void bar (void); + +void * +foo (void) +{ + return &bar; +} + +/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*bar@GOTPCREL" } } */ +/* { dg-final { scan-assembler-not "\(mov|lea\)\(l|q\)\[ \t\]*\(\\\$|\)bar," } } */ Index: testsuite/gcc.target/i386/pr67400-2.c =================================================================== --- testsuite/gcc.target/i386/pr67400-2.c (nonexistent) +++ testsuite/gcc.target/i386/pr67400-2.c (working copy) @@ -0,0 +1,14 @@ +/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +extern void bar (void); +extern void *p; + +void +foo (void) +{ + p = &bar; +} + +/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*bar@GOTPCREL" } } */ +/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*\\\$bar," } } */ Index: testsuite/gcc.target/i386/pr67400-3.c =================================================================== --- testsuite/gcc.target/i386/pr67400-3.c (nonexistent) +++ testsuite/gcc.target/i386/pr67400-3.c (working copy) @@ -0,0 +1,16 @@ +/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +static void +bar (void) +{ +} + +void * +foo (void) +{ + return &bar; +} + +/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*\\\$bar," } } */ +/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*bar@GOTPCREL" } } */ Index: testsuite/gcc.target/i386/pr67400-4.c =================================================================== --- testsuite/gcc.target/i386/pr67400-4.c (nonexistent) +++ testsuite/gcc.target/i386/pr67400-4.c (working copy) @@ -0,0 +1,13 @@ +/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +extern void bar (void) __attribute__ ((visibility ("hidden"))); + +void * +foo (void) +{ + return &bar; +} + +/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*\\\$bar," } } */ +/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*bar@GOTPCREL" } } */ Index: testsuite/gcc.target/i386/pr67400-5.c =================================================================== --- testsuite/gcc.target/i386/pr67400-5.c (nonexistent) +++ testsuite/gcc.target/i386/pr67400-5.c (working copy) @@ -0,0 +1,11 @@ +/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +extern void foo (void); +extern void bar (int, int, int, int, int, int, void *); + +void +x (void) +{ + bar (1, 2, 3, 4, 5, 6, foo); +} Index: testsuite/gcc.target/i386/pr67400-6.c =================================================================== --- testsuite/gcc.target/i386/pr67400-6.c (nonexistent) +++ testsuite/gcc.target/i386/pr67400-6.c (working copy) @@ -0,0 +1,13 @@ +/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +extern int bar (void); + +int +check (void *p) +{ + return p != &bar; +} + +/* { dg-final { scan-assembler "cmp\(l|q\)\[ \t\]*.*bar@GOTPCREL" } } */ +/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*\\\$bar," } } */ Index: testsuite/gcc.target/i386/pr67400-7.c =================================================================== --- testsuite/gcc.target/i386/pr67400-7.c (nonexistent) +++ testsuite/gcc.target/i386/pr67400-7.c (working copy) @@ -0,0 +1,13 @@ +/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +extern void bar (void); + +void * +foo (void) +{ + return &bar+1; +} + +/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*bar@GOTPCREL" } } */ +/* { dg-final { scan-assembler-not "\(mov|lea\)\(l|q\)\[ \t\]*\(\\\$|\)bar," } } */