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| author | Bernd Schmidt <bernd.schmidt@codesourcery.com> | 2010-03-19 18:41:22 +0000 |
|---|---|---|
| committer | Bernd Schmidt <bernds@gcc.gnu.org> | 2010-03-19 18:41:22 +0000 |
| commit | c99102b8b4cc0ec725c741b13c6f406bbd924c73 (patch) | |
| tree | 2bcf096e2c7a2d0589b6d0f349bfdd7ccaef90f5 /gcc/config/arm/arm.c | |
| parent | 002b2dee5d23dff9cc0a7f3196838534bc084da4 (diff) | |
| download | gcc-c99102b8b4cc0ec725c741b13c6f406bbd924c73.zip gcc-c99102b8b4cc0ec725c741b13c6f406bbd924c73.tar.gz gcc-c99102b8b4cc0ec725c741b13c6f406bbd924c73.tar.bz2 | |
re PR target/40697 (inefficient code to extract least bits from an integer value)
gcc/
PR target/40697
* optabs.c (avoid_expensive_constant): Use rtx_cost to find out
the cost of loading the constant rather than assuming
COSTS_N_INSNS (1).
* config/arm/arm.c (thumb1_rtx_costs) <case CONST_INT>: If the
outer code is AND, do the same tests as the andsi3 expander and
return COSTS_N_INSNS (1) if and is cheap.
testsuite/
PR target/40697
* gcc.target/arm/thumb-andsi.c: New test.
From-SVN: r157582
Diffstat (limited to 'gcc/config/arm/arm.c')
| -rw-r--r-- | gcc/config/arm/arm.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index 870e56e..cc023c1 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -6228,6 +6228,15 @@ thumb1_rtx_costs (rtx x, enum rtx_code code, enum rtx_code outer) else if ((outer == IOR || outer == XOR || outer == AND) && INTVAL (x) < 256 && INTVAL (x) >= -256) return COSTS_N_INSNS (1); + else if (outer == AND) + { + int i; + /* This duplicates the tests in the andsi3 expander. */ + for (i = 9; i <= 31; i++) + if ((((HOST_WIDE_INT) 1) << i) - 1 == INTVAL (x) + || (((HOST_WIDE_INT) 1) << i) - 1 == ~INTVAL (x)) + return COSTS_N_INSNS (2); + } else if (outer == ASHIFT || outer == ASHIFTRT || outer == LSHIFTRT) return 0; |