diff options
author | Senthil Kumar Selvaraj <senthil_kumar.selvaraj@atmel.com> | 2015-11-19 17:30:24 +0000 |
---|---|---|
committer | Jeff Law <law@gcc.gnu.org> | 2015-11-19 10:30:24 -0700 |
commit | 1014b6f54b75b690b81dfac4b284961c2fb51646 (patch) | |
tree | c46d7a664854f1eb101011a8c8f91af5e052887e | |
parent | 04a9bb6ec35a925ec15fcaafe16124748c3bfcc9 (diff) | |
download | gcc-1014b6f54b75b690b81dfac4b284961c2fb51646.zip gcc-1014b6f54b75b690b81dfac4b284961c2fb51646.tar.gz gcc-1014b6f54b75b690b81dfac4b284961c2fb51646.tar.bz2 |
[Patch, vrp] Allow VRP type conversion folding only for widenings upto word mode
* tree.h (desired_pro_or_demotion_p): New function.
* tree-vrp.c (simplify_cond_using_ranges): Call it.
* gcc.dg/tree-ssa/vrp98.c: New testcase.
* gcc.target/avr/uint8-single-reg.c: New testcase.
From-SVN: r230618
-rw-r--r-- | gcc/ChangeLog | 5 | ||||
-rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/vrp98.c | 41 | ||||
-rw-r--r-- | gcc/testsuite/gcc.target/avr/uint8-single-reg.c | 24 | ||||
-rw-r--r-- | gcc/tree-vrp.c | 3 | ||||
-rw-r--r-- | gcc/tree.h | 14 |
6 files changed, 91 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 1013d8f..9e8383f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2015-11-19 Senthil Kumar Selvaraj <senthil_kumar.selvaraj@atmel.com> + + * tree.h (desired_pro_or_demotion_p): New function. + * tree-vrp.c (simplify_cond_using_ranges): Call it. + 2015-11-19 Jakub Jelinek <jakub@redhat.com> Manuel López-Ibáñez <manu@gcc.gnu.org> diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 2d4962d..4a4c4ce 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2015-11-19 Senthil Kumar Selvaraj <senthil_kumar.selvaraj@atmel.com> + + * gcc.dg/tree-ssa/vrp98.c: New testcase. + * gcc.target/avr/uint8-single-reg.c: New testcase. + 2015-11-19 Jakub Jelinek <jakub@redhat.com> PR c++/67409 diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp98.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp98.c new file mode 100644 index 0000000..982f091 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp98.c @@ -0,0 +1,41 @@ +/* { dg-do compile } */ +/* { dg-require-effective-target int128 } */ +/* { dg-options "-Os -fdump-tree-vrp1-details" } */ + +#include <stdint.h> +#include <limits.h> + +typedef unsigned int word __attribute__((mode(word))); +typedef unsigned __int128 bigger_than_word; + +int +foo (bigger_than_word a, word b, uint8_t c) +{ + /* Must fold use of t1 into use of b, as b is no wider than word_mode. */ + const uint8_t t1 = b % UCHAR_MAX; + + /* Must NOT fold use of t2 into use of a, as a is wider than word_mode. */ + const uint8_t t2 = a % UCHAR_MAX; + + /* Must fold use of t3 into use of c, as c is narrower than t3. */ + const uint32_t t3 = (const uint32_t)(c >> 1); + + uint16_t ret = 0; + + if (t1 == 1) + ret = 20; + else if (t2 == 2) + ret = 30; + else if (t3 == 3) + ret = 40; + /* Th extra condition below is necessary to prevent a prior pass from + folding away the cast. Ignored in scan-tree-dump. */ + else if (t3 == 4) + ret = 50; + + return ret; +} + +/* { dg-final { scan-tree-dump "Folded into: if \\(_\[0-9\]+ == 1\\)" "vrp1" } } */ +/* { dg-final { scan-tree-dump-not "Folded into: if \\(_\[0-9\]+ == 2\\)" "vrp1" } } */ +/* { dg-final { scan-tree-dump "Folded into: if \\(_\[0-9\]+ == 3\\)" "vrp1" } } */ diff --git a/gcc/testsuite/gcc.target/avr/uint8-single-reg.c b/gcc/testsuite/gcc.target/avr/uint8-single-reg.c new file mode 100644 index 0000000..291b56c --- /dev/null +++ b/gcc/testsuite/gcc.target/avr/uint8-single-reg.c @@ -0,0 +1,24 @@ +/* { dg-do compile } */ +/* { dg-options "-Os" } */ + +/* This testcase verifies that a uint8_t variable assigned from a wider variable + with the same range is held in a single register. VRP must not fold away the + conversion and use two regs to hold the uint16_t - widenings are ok only upto + word mode (1 byte for AVR). +*/ + +unsigned int foo(const unsigned int wvalue) +{ + const unsigned char type = (wvalue >> 8); + unsigned int size = 0; + + if (type == 1) + { + size = 20; + } + return size; +} + +/* { dg-final { scan-assembler "cpi r25,lo8\\(1\\)" } } */ +/* { dg-final { scan-assembler-not "cpc r\\d+,__zero_reg__" } } */ + diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 736082b..f2c948c 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -9459,7 +9459,8 @@ simplify_cond_using_ranges (gcond *stmt) innerop = gimple_assign_rhs1 (def_stmt); if (TREE_CODE (innerop) == SSA_NAME - && !POINTER_TYPE_P (TREE_TYPE (innerop))) + && !POINTER_TYPE_P (TREE_TYPE (innerop)) + && desired_pro_or_demotion_p (TREE_TYPE (innerop), TREE_TYPE (op0))) { value_range *vr = get_value_range (innerop); @@ -5358,4 +5358,18 @@ get_decl_source_range (tree decl) return get_range_from_loc (line_table, loc); } +/* Return true if it makes sense to promote/demote from_type to to_type. */ +inline bool +desired_pro_or_demotion_p (const_tree to_type, const_tree from_type) +{ + unsigned int to_type_precision = TYPE_PRECISION (to_type); + + /* OK to promote if to_type is no bigger than word_mode. */ + if (to_type_precision <= GET_MODE_PRECISION (word_mode)) + return true; + + /* Otherwise, allow only if narrowing or same precision conversions. */ + return to_type_precision <= TYPE_PRECISION (from_type); +} + #endif /* GCC_TREE_H */ |