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| author | H.J. Lu <hongjiu.lu@intel.com> | 2010-08-17 15:49:32 +0000 |
|---|---|---|
| committer | H.J. Lu <hjl@gcc.gnu.org> | 2010-08-17 08:49:32 -0700 |
| commit | 1c111d0a5874d378f3e80c057255b2edb1bf0836 (patch) | |
| tree | 2dd7ee12e470dc49dda87653d8123bb331b108a4 /gcc | |
| parent | e2a1fcf0add4aaa44ac743278eacf623d9f39f62 (diff) | |
| download | gcc-1c111d0a5874d378f3e80c057255b2edb1bf0836.zip gcc-1c111d0a5874d378f3e80c057255b2edb1bf0836.tar.gz gcc-1c111d0a5874d378f3e80c057255b2edb1bf0836.tar.bz2 | |
Try to avoid lea if possible.
2010-08-17 H.J. Lu <hongjiu.lu@intel.com>
* config/i386/i386.c (ix86_lea_for_add_ok): For !TARGET_OPT_AGU
or optimizing for size, always avoid lea if possible.
* config/i386/i386.md (*add<mode>_1): Always avoid lea if
possible.
From-SVN: r163310
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/config/i386/i386.c | 18 | ||||
| -rw-r--r-- | gcc/config/i386/i386.md | 11 |
3 files changed, 21 insertions, 16 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 61f3c19..47aa331 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2010-08-17 H.J. Lu <hongjiu.lu@intel.com> + + * config/i386/i386.c (ix86_lea_for_add_ok): For !TARGET_OPT_AGU + or optimizing for size, always avoid lea if possible. + + * config/i386/i386.md (*add<mode>_1): Always avoid lea if + possible. + 2010-08-17 Iain Sandoe <iains@gcc.gnu.org> * unwind-dw2-fde-darwin.c (_darwin10_Unwind_FindEnclosingFunction): diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index b925122..f1d4402 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -14802,10 +14802,10 @@ distance_agu_use (unsigned int regno0, rtx insn) #define IX86_LEA_PRIORITY 2 /* Return true if it is ok to optimize an ADD operation to LEA - operation to avoid flag register consumation. For the processors - like ATOM, if the destination register of LEA holds an actual - address which will be used soon, LEA is better and otherwise ADD - is better. */ + operation to avoid flag register consumation. For most processors, + ADD is faster than LEA. For the processors like ATOM, if the + destination register of LEA holds an actual address which will be + used soon, LEA is better and otherwise ADD is better. */ bool ix86_lea_for_add_ok (enum rtx_code code ATTRIBUTE_UNUSED, @@ -14813,16 +14813,14 @@ ix86_lea_for_add_ok (enum rtx_code code ATTRIBUTE_UNUSED, { unsigned int regno0 = true_regnum (operands[0]); unsigned int regno1 = true_regnum (operands[1]); - unsigned int regno2; - - if (!TARGET_OPT_AGU || optimize_function_for_size_p (cfun)) - return regno0 != regno1; - - regno2 = true_regnum (operands[2]); + unsigned int regno2 = true_regnum (operands[2]); /* If a = b + c, (a!=b && a!=c), must use lea form. */ if (regno0 != regno1 && regno0 != regno2) return true; + + if (!TARGET_OPT_AGU || optimize_function_for_size_p (cfun)) + return false; else { int dist_define, dist_use; diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md index 0041158..f6ab0e2 100644 --- a/gcc/config/i386/i386.md +++ b/gcc/config/i386/i386.md @@ -5813,8 +5813,10 @@ } default: - /* Use add as much as possible to replace lea for AGU optimization. */ - if (which_alternative == 2 && TARGET_OPT_AGU) + /* This alternative was added for TARGET_OPT_AGU to use add as + much as possible. But add is also faster than lea for + !TARGET_OPT_AGU. */ + if (which_alternative == 2) return "add{<imodesuffix>}\t{%1, %0|%0, %1}"; gcc_assert (rtx_equal_p (operands[0], operands[1])); @@ -5825,10 +5827,7 @@ } } [(set (attr "type") - (cond [(and (eq_attr "alternative" "2") - (eq (symbol_ref "TARGET_OPT_AGU") (const_int 0))) - (const_string "lea") - (eq_attr "alternative" "3") + (cond [(eq_attr "alternative" "3") (const_string "lea") (match_operand:SWI48 2 "incdec_operand" "") (const_string "incdec") |