From 60ba7cd38dff1e64ffcfac04665e32caebcbe6fe Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Sun, 24 Sep 2017 14:37:09 -0700 Subject: [PATCH] x32: Encode %esp as %rsp to avoid 0x67 prefix Since the upper 32 bits of stack register are always zero for x32, we can encode %esp as %rsp to avoid 0x67 prefix in address if there is no index or base register. gcc/ PR target/82267 * config/i386/i386.c (ix86_print_operand_address_as): Encode %esp as %rsp to avoid 0x67 prefix if there is no index or base register. gcc/testsuite/ PR target/82267 * gcc.target/i386/pr82267.c: New test. From-SVN: r253127 --- gcc/ChangeLog | 7 +++++++ gcc/config/i386/i386.c | 8 ++++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.target/i386/pr82267.c | 14 ++++++++++++++ 4 files changed, 34 insertions(+) create mode 100644 gcc/testsuite/gcc.target/i386/pr82267.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 041e47f..b92347e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2017-09-24 Uros Bizjak + + PR target/82267 + * config/i386/i386.c (ix86_print_operand_address_as): Encode + %esp as %rsp to avoid 0x67 prefix if there is no index or base + register. + 2017-09-23 Uros Bizjak PR bootstrap/82306 diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 7434aae..293287c 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -19953,6 +19953,14 @@ ix86_print_operand_address_as (FILE *file, rtx addr, code = 'k'; } + /* Since the upper 32 bits of RSP are always zero for x32, we can + encode %esp as %rsp to avoid 0x67 prefix if there is no index or + base register. */ + if (TARGET_X32 && Pmode == SImode + && ((!index && base && REGNO (base) == SP_REG) + || (!base && index && REGNO (index) == SP_REG))) + code = 'q'; + if (ASSEMBLER_DIALECT == ASM_ATT) { if (disp) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 21e6e2d..18c4a26 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-09-24 H.J. Lu + + PR target/82267 + * gcc.target/i386/pr82267.c: New test. + 2017-09-24 Thomas Koenig PR fortran/66328 diff --git a/gcc/testsuite/gcc.target/i386/pr82267.c b/gcc/testsuite/gcc.target/i386/pr82267.c new file mode 100644 index 0000000..5e4b271 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr82267.c @@ -0,0 +1,14 @@ +/* { dg-do compile { target { ! ia32 } } } */ +/* { dg-require-effective-target maybe_x32 } */ +/* { dg-options "-O2 -mx32 -maddress-mode=short" } */ + +int +stackuse (void) +{ + volatile int foo = 2; + return foo * 3; +} + +/* Verify we that use %rsp to access stack. */ +/* { dg-final { scan-assembler-not "%esp" } } */ +/* { dg-final { scan-assembler "%rsp" } } */ -- 2.7.4