diff options
| author | Yvan Roux <yvan.roux@linaro.org> | 2016-01-12 16:25:46 +0100 |
|---|---|---|
| committer | Linaro Code Review <review@review.linaro.org> | 2016-01-13 09:56:41 +0000 |
| commit | 428ded17977c8142625804eb8f7545ae7bb06f7b (patch) | |
| tree | 62dc59eef237f76cc5179402002a1d5a90118d32 | |
| parent | 70d504cf4dac578be53e6513ca9ed8a8adc2cdb3 (diff) | |
gcc/
Backport from trunk r230786.
2015-11-24 Segher Boessenkool <segher@kernel.crashing.org>
PR rtl-optimization/68381
* combine.c (is_parallel_of_n_reg_sets): Return false if the pattern
is poisoned.
gcc/testsuite/
Backport from trunk r230809.
2015-11-24 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
PR rtl-optimization/68381
* gcc.c-torture/execute/pr68381.c: New test.
gcc/
Backport from trunk r230946.
2015-11-26 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
* combine.c (subst): Do not return clobber of zero in widening mult
case. Just return x unchanged if it is a no-op substitution.
Change-Id: I3a644b62bce1ddd7d24ebd3b2c604076e040d755
| -rw-r--r-- | gcc/combine.c | 16 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.c-torture/execute/pr68381.c | 22 |
2 files changed, 29 insertions, 9 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index ba9dd61626f..c903db2c8b0 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -2558,7 +2558,8 @@ is_parallel_of_n_reg_sets (rtx pat, int n) || !REG_P (SET_DEST (XVECEXP (pat, 0, i)))) return false; for ( ; i < len; i++) - if (GET_CODE (XVECEXP (pat, 0, i)) != CLOBBER) + if (GET_CODE (XVECEXP (pat, 0, i)) != CLOBBER + || XEXP (XVECEXP (pat, 0, i), 0) == const0_rtx) return false; return true; @@ -5316,7 +5317,7 @@ subst (rtx x, rtx from, rtx to, int in_dest, int in_cond, int unique_copy) || GET_CODE (SET_DEST (x)) == PC)) fmt = "ie"; - /* Substituting into the operands of a widening MULT is not likely + /* Trying to simplify the operands of a widening MULT is not likely to create RTL matching a machine insn. */ if (code == MULT && (GET_CODE (XEXP (x, 0)) == ZERO_EXTEND @@ -5324,13 +5325,10 @@ subst (rtx x, rtx from, rtx to, int in_dest, int in_cond, int unique_copy) && (GET_CODE (XEXP (x, 1)) == ZERO_EXTEND || GET_CODE (XEXP (x, 1)) == SIGN_EXTEND) && REG_P (XEXP (XEXP (x, 0), 0)) - && REG_P (XEXP (XEXP (x, 1), 0))) - { - if (from == to) - return x; - else - return gen_rtx_CLOBBER (GET_MODE (x), const0_rtx); - } + && REG_P (XEXP (XEXP (x, 1), 0)) + && from == to) + return x; + /* Get the mode of operand 0 in case X is now a SIGN_EXTEND of a constant. */ diff --git a/gcc/testsuite/gcc.c-torture/execute/pr68381.c b/gcc/testsuite/gcc.c-torture/execute/pr68381.c new file mode 100644 index 00000000000..cb6abcb265b --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr68381.c @@ -0,0 +1,22 @@ +/* { dg-options "-O -fexpensive-optimizations -fno-tree-bit-ccp" } */ + +__attribute__ ((noinline, noclone)) +int +foo (unsigned short x, unsigned short y) +{ + int r; + if (__builtin_mul_overflow (x, y, &r)) + __builtin_abort (); + return r; +} + +int +main (void) +{ + int x = 1; + int y = 2; + if (foo (x, y) != x * y) + __builtin_abort (); + return 0; +} + |