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| author | Segher Boessenkool <segher@kernel.crashing.org> | 2017-12-13 15:05:57 +0100 |
|---|---|---|
| committer | Segher Boessenkool <segher@gcc.gnu.org> | 2017-12-13 15:05:57 +0100 |
| commit | 2046f23f52d5ed4299f12e5f98a88491e4936c44 (patch) | |
| tree | fdd3d7a0babdfbf3b3c64e2de65288c9cc43e89b | |
| parent | 2b031ef48e365e256495a3e6d226a59f2290444f (diff) | |
| download | gcc-2046f23f52d5ed4299f12e5f98a88491e4936c44.zip gcc-2046f23f52d5ed4299f12e5f98a88491e4936c44.tar.gz gcc-2046f23f52d5ed4299f12e5f98a88491e4936c44.tar.bz2 | |
combine: Fix PR83393
In move_deaths we move a REG_DEAD note if the instruction combination
has extended the lifetime of a register so that the existing note is
no longer valid. We find that note using reg_stat, but what that finds
can refer to a later insn. If so, we cannot use the cached value. This
patch implements that.
PR rtl-optimization/83393
* combine.c (move_deaths): If reg_stat points to a too new insn in
last_death, do not use it: find the proper insn instead.
gcc/testsuite/
PR rtl-optimization/83393
* gcc.dg/pr83393.c: New testcase.
From-SVN: r255606
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/combine.c | 2 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr83393.c | 38 |
4 files changed, 50 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9b4829d..5d992af 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2017-12-13 Segher Boessenkool <segher@kernel.crashing.org> + + PR rtl-optimization/83393 + * combine.c (move_deaths): If reg_stat points to a too new insn in + last_death, do not use it: find the proper insn instead. + 2017-12-12 Jeff Law <law@redhat.com> PR tree-optimization/83298 diff --git a/gcc/combine.c b/gcc/combine.c index b6410c3..eb737f6 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -13880,7 +13880,7 @@ move_deaths (rtx x, rtx maybe_kill_insn, int from_luid, rtx_insn *to_insn, /* If we do not know where the register died, it may still die between FROM_LUID and TO_INSN. If so, find it. This is PR83304. */ - if (!where_dead) + if (!where_dead || DF_INSN_LUID (where_dead) >= DF_INSN_LUID (to_insn)) { rtx_insn *insn = prev_real_insn (to_insn); while (insn diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 7159ab9..c5f1d44 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-12-13 Segher Boessenkool <segher@kernel.crashing.org> + + PR rtl-optimization/83393 + * gcc.dg/pr83393.c: New testcase. + 2017-12-13 Nathan Sidwell <nathan@acm.org> PR c++/15272 diff --git a/gcc/testsuite/gcc.dg/pr83393.c b/gcc/testsuite/gcc.dg/pr83393.c new file mode 100644 index 0000000..a9a6b33 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr83393.c @@ -0,0 +1,38 @@ +/* PR rtl-optimization/83393 */ +/* { dg-do run } */ +/* { dg-options "-O2 -fno-forward-propagate -fno-tree-bit-ccp" } */ + +typedef unsigned char u8; +typedef unsigned short u16; +typedef unsigned int u32; +typedef unsigned long long u64; + +u32 a, d; +u64 b; +u8 c; + +static u64 __attribute__ ((noinline, noclone)) +foo (u16 f, u64 g) +{ + f <<= 15; + f *= d; + f -= g %= 44; + f <<= f <= g; + c = 255; + c >>= (u8) f == 0; + f *= g; + c -= ~c; + return f + a + b + f; +} + +int +main (void) +{ +#if (__SIZEOF_LONG_LONG__ == 8 && __SIZEOF_INT__ == 4 \ + && __SIZEOF_SHORT__ == 2 && __CHAR_BIT__ == 8) + u64 x = foo (3, 0xE6C0011BBA6DBD7LL); + if (x != 0x1f66e) + __builtin_abort (); +#endif + return 0; +} |