This change drops forced alignment to 8 if requested alignment is higher than 8: before the patch, -falign-functions=9 was generating
.p2align 4,,8 .p2align 3 which means: "align to 16 if the skip is 8 bytes or less; else align to 8". After this change, ".p2align 3" is not emitted. This behavior will be implemented differently by the next patch. The new SUBALIGN_LOG define will be used by the next patch. While we are here, avoid generating ".p2align N,,2^N-1" - it is functionally equivalent to ".p2align N". In this case, use the latter. 2016-09-27 Denys Vlasenko <dvlas...@redhat.com> * config/i386/dragonfly.h: (ASM_OUTPUT_MAX_SKIP_ALIGN): Use a simpler align directive also if MAXSKIP = ALIGN-1. * config/i386/gas.h (ASM_OUTPUT_MAX_SKIP_ALIGN): Likewise. * config/i386/lynx.h (ASM_OUTPUT_MAX_SKIP_ALIGN): Likewise. * config/i386/netbsd-elf.h (ASM_OUTPUT_MAX_SKIP_ALIGN): Likewise. * config/i386/i386.h (ASM_OUTPUT_MAX_SKIP_PAD): Likewise. * config/i386/freebsd.h (ASM_OUTPUT_MAX_SKIP_ALIGN): Remove "If N is large, do at least 8 byte alignment" code. Add SUBALIGN_LOG define. Use a simpler align directive also if MAXSKIP = ALIGN-1. * config/i386/gnu-user.h (ASM_OUTPUT_MAX_SKIP_ALIGN): Likewise. * config/i386/iamcu.h (ASM_OUTPUT_MAX_SKIP_ALIGN): Likewise. * config/i386/openbsdelf.h (ASM_OUTPUT_MAX_SKIP_ALIGN): Likewise. * config/i386/x86-64.h (ASM_OUTPUT_MAX_SKIP_ALIGN): Likewise. Index: gcc/config/i386/dragonfly.h =================================================================== --- gcc/config/i386/dragonfly.h (revision 239860) +++ gcc/config/i386/dragonfly.h (working copy) @@ -69,10 +69,12 @@ see the files COPYING3 and COPYING.RUNTIME respect #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN #undef ASM_OUTPUT_MAX_SKIP_ALIGN -#define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE, LOG, MAX_SKIP) \ - if ((LOG) != 0) { \ - if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ - else fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ +#define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE, LOG, MAX_SKIP) \ + if ((LOG) != 0) { \ + if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1<<(LOG))-1) \ + fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ + else \ + fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ } #endif Index: gcc/config/i386/freebsd.h =================================================================== --- gcc/config/i386/freebsd.h (revision 239860) +++ gcc/config/i386/freebsd.h (working copy) @@ -92,9 +92,9 @@ along with GCC; see the file COPYING3. If not see /* A C statement to output to the stdio stream FILE an assembler command to advance the location counter to a multiple of 1<<LOG - bytes if it is within MAX_SKIP bytes. + bytes if it is within MAX_SKIP bytes. */ - This is used to align code labels according to Intel recommendations. */ +#define SUBALIGN_LOG 3 #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN #undef ASM_OUTPUT_MAX_SKIP_ALIGN @@ -101,16 +101,10 @@ along with GCC; see the file COPYING3. If not see #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \ do { \ if ((LOG) != 0) { \ - if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ - else { \ + if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1<<(LOG))-1) \ + fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ + else \ fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ - /* Make sure that we have at least 8 byte alignment if > 8 byte \ - alignment is preferred. */ \ - if ((LOG) > 3 \ - && (1 << (LOG)) > ((MAX_SKIP) + 1) \ - && (MAX_SKIP) >= 7) \ - fputs ("\t.p2align 3\n", (FILE)); \ - } \ } \ } while (0) #endif Index: gcc/config/i386/gas.h =================================================================== --- gcc/config/i386/gas.h (revision 239860) +++ gcc/config/i386/gas.h (working copy) @@ -72,10 +72,12 @@ along with GCC; see the file COPYING3. If not see #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN # define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \ - if ((LOG) != 0) {\ - if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ - else fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ - } + if ((LOG) != 0) { \ + if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1<<(LOG))-1) \ + fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ + else \ + fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ + } #endif /* A C statement or statements which output an assembler instruction Index: gcc/config/i386/gnu-user.h =================================================================== --- gcc/config/i386/gnu-user.h (revision 239860) +++ gcc/config/i386/gnu-user.h (working copy) @@ -94,24 +94,18 @@ along with GCC; see the file COPYING3. If not see /* A C statement to output to the stdio stream FILE an assembler command to advance the location counter to a multiple of 1<<LOG - bytes if it is within MAX_SKIP bytes. + bytes if it is within MAX_SKIP bytes. */ - This is used to align code labels according to Intel recommendations. */ +#define SUBALIGN_LOG 3 #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \ do { \ if ((LOG) != 0) { \ - if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ - else { \ + if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1<<(LOG))-1) \ + fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ + else \ fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ - /* Make sure that we have at least 8 byte alignment if > 8 byte \ - alignment is preferred. */ \ - if ((LOG) > 3 \ - && (1 << (LOG)) > ((MAX_SKIP) + 1) \ - && (MAX_SKIP) >= 7) \ - fputs ("\t.p2align 3\n", (FILE)); \ - } \ } \ } while (0) #endif Index: gcc/config/i386/i386.h =================================================================== --- gcc/config/i386/i386.h (revision 239860) +++ gcc/config/i386/i386.h (working copy) @@ -2271,7 +2271,7 @@ do { \ #define ASM_OUTPUT_MAX_SKIP_PAD(FILE, LOG, MAX_SKIP) \ if ((LOG) != 0) \ { \ - if ((MAX_SKIP) == 0) \ + if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1<<(LOG))-1) \ fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ else \ fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ Index: gcc/config/i386/iamcu.h =================================================================== --- gcc/config/i386/iamcu.h (revision 239860) +++ gcc/config/i386/iamcu.h (working copy) @@ -62,23 +62,17 @@ see the files COPYING3 and COPYING.RUNTIME respect /* A C statement to output to the stdio stream FILE an assembler command to advance the location counter to a multiple of 1<<LOG - bytes if it is within MAX_SKIP bytes. + bytes if it is within MAX_SKIP bytes. */ - This is used to align code labels according to Intel recommendations. */ +#define SUBALIGN_LOG 3 #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \ do { \ if ((LOG) != 0) { \ - if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ - else { \ + if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1<<(LOG))-1) \ + fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ + else \ fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ - /* Make sure that we have at least 8 byte alignment if > 8 byte \ - alignment is preferred. */ \ - if ((LOG) > 3 \ - && (1 << (LOG)) > ((MAX_SKIP) + 1) \ - && (MAX_SKIP) >= 7) \ - fputs ("\t.p2align 3\n", (FILE)); \ - } \ } \ } while (0) Index: gcc/config/i386/lynx.h =================================================================== --- gcc/config/i386/lynx.h (revision 239860) +++ gcc/config/i386/lynx.h (working copy) @@ -61,8 +61,10 @@ along with GCC; see the file COPYING3. If not see #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \ do { \ if ((LOG) != 0) { \ - if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ - else fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ + if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1<<(LOG))-1) \ + fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ + else \ + fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ } \ } while (0) #endif Index: gcc/config/i386/netbsd-elf.h =================================================================== --- gcc/config/i386/netbsd-elf.h (revision 239860) +++ gcc/config/i386/netbsd-elf.h (working copy) @@ -104,8 +104,10 @@ along with GCC; see the file COPYING3. If not see #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE, LOG, MAX_SKIP) \ if ((LOG) != 0) { \ - if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ - else fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ + if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1<<(LOG))-1) \ + fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ + else \ + fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ } #endif Index: gcc/config/i386/openbsdelf.h =================================================================== --- gcc/config/i386/openbsdelf.h (revision 239860) +++ gcc/config/i386/openbsdelf.h (working copy) @@ -63,24 +63,18 @@ along with GCC; see the file COPYING3. If not see /* A C statement to output to the stdio stream FILE an assembler command to advance the location counter to a multiple of 1<<LOG - bytes if it is within MAX_SKIP bytes. + bytes if it is within MAX_SKIP bytes. */ - This is used to align code labels according to Intel recommendations. */ +#define SUBALIGN_LOG 3 #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \ do { \ if ((LOG) != 0) { \ - if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ - else { \ + if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1<<(LOG))-1) \ + fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ + else \ fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ - /* Make sure that we have at least 8 byte alignment if > 8 byte \ - alignment is preferred. */ \ - if ((LOG) > 3 \ - && (1 << (LOG)) > ((MAX_SKIP) + 1) \ - && (MAX_SKIP) >= 7) \ - fputs ("\t.p2align 3\n", (FILE)); \ - } \ } \ } while (0) #endif Index: gcc/config/i386/x86-64.h =================================================================== --- gcc/config/i386/x86-64.h (revision 239860) +++ gcc/config/i386/x86-64.h (working copy) @@ -61,20 +61,16 @@ see the files COPYING3 and COPYING.RUNTIME respect /* This is used to align code labels according to Intel recommendations. */ +#define SUBALIGN_LOG 3 + #ifdef HAVE_GAS_MAX_SKIP_P2ALIGN #define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \ do { \ if ((LOG) != 0) { \ - if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ - else { \ + if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1<<(LOG))-1) \ + fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ + else \ fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ - /* Make sure that we have at least 8 byte alignment if > 8 byte \ - alignment is preferred. */ \ - if ((LOG) > 3 \ - && (1 << (LOG)) > ((MAX_SKIP) + 1) \ - && (MAX_SKIP) >= 7) \ - fputs ("\t.p2align 3\n", (FILE)); \ - } \ } \ } while (0) #undef ASM_OUTPUT_MAX_SKIP_PAD @@ -81,7 +77,7 @@ see the files COPYING3 and COPYING.RUNTIME respect #define ASM_OUTPUT_MAX_SKIP_PAD(FILE, LOG, MAX_SKIP) \ if ((LOG) != 0) \ { \ - if ((MAX_SKIP) == 0) \ + if ((MAX_SKIP) == 0 || (MAX_SKIP) >= (1<<(LOG))-1) \ fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ else \ fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \