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| author | Andrew Pinski <pinskia@gmail.com> | 2023-10-27 19:23:52 -0700 |
|---|---|---|
| committer | Andrew Pinski <pinskia@gmail.com> | 2023-10-30 19:15:25 -0700 |
| commit | 541b754c77ab806a9dae9bbaae69722e2c36f0f0 (patch) | |
| tree | 6c8b211cd6320eaa341e557604401896ad75cd30 | |
| parent | 598fdb5290dcf76ef23e993409e22f1512ff835a (diff) | |
| download | gcc-541b754c77ab806a9dae9bbaae69722e2c36f0f0.zip gcc-541b754c77ab806a9dae9bbaae69722e2c36f0f0.tar.gz gcc-541b754c77ab806a9dae9bbaae69722e2c36f0f0.tar.bz2 | |
MATCH: Add some more value_replacement simplifications to match
This moves a few more value_replacements simplifications to match.
/* a == 1 ? b : a * b -> a * b */
/* a == 1 ? b : b / a -> b / a */
/* a == -1 ? b : a & b -> a & b */
Also adds a testcase to show can we catch these where value_replacement would not
(but other passes would).
Bootstrapped and tested on x86_64-linux-gnu with no regressions.
gcc/ChangeLog:
* match.pd (`a == 1 ? b : a OP b`): New pattern.
(`a == -1 ? b : a & b`): New pattern.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/phi-opt-value-4.c: New test.
| -rw-r--r-- | gcc/match.pd | 18 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/phi-opt-value-4.c | 36 |
2 files changed, 54 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 22899c5..070db98 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -4159,6 +4159,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (cond (eq @0 integer_zerop) @1 (op@2 @1 @0)) @2)) +/* a == 1 ? b : b / a -> b / a */ +(for op (trunc_div ceil_div floor_div round_div exact_div) + (simplify + (cond (eq @0 integer_onep) @1 (op@2 @1 @0)) + @2)) + +/* a == 1 ? b : a * b -> a * b */ +(for op (mult) + (simplify + (cond (eq @0 integer_onep) @1 (op:c@2 @1 @0)) + @2)) + +/* a == -1 ? b : a & b -> a & b */ +(for op (bit_and) + (simplify + (cond (eq @0 integer_all_onesp) @1 (op:c@2 @1 @0)) + @2)) + /* Simplifications of shift and rotates. */ (for rotate (lrotate rrotate) diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-value-4.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-value-4.c new file mode 100644 index 0000000..380082c --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-value-4.c @@ -0,0 +1,36 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -fdump-tree-fre3 -fdump-tree-phiopt1 -fdump-tree-optimized" } */ + +[[gnu::const]] +int constcall(int); + +int fdiv(int a, int b) +{ + int c = b/a; + int t = constcall(c); + int d; + if (a == 1) d = b; else d = c; + return constcall(d) + t; +} +int fmult(int a, int b) +{ + int c = b*a; + int t = constcall(c); + int d; + if (a == 1) d = b; else d = c; + return constcall(d) + t; +} +int fand(int a, int b) +{ + int c = b&a; + int t = constcall(c); + int d; + if (a == -1) d = b; else d = c; + return constcall(d) + t; +} + +/* Should be able to optimize away the if statements in phiopt1. */ +/* { dg-final { scan-tree-dump-not "if " "phiopt1" } } */ +/* fre3 should be optimize each function to just `return constcall(a OP b) * 2;`. */ +/* { dg-final { scan-tree-dump-times "constcall " 3 "fre3" } } */ +/* { dg-final { scan-tree-dump-times "constcall " 3 "optimized" } } */ |