diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/combine.c | 24 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr77309.c | 14 |
4 files changed, 45 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index c237044..1d1cbb7 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2016-11-07 Bernd Schmidt <bschmidt@redhat.com> + + PR rtl-optimization/77309 + * combine.c (make_compound_operation): Allow EQ for IN_CODE, and + don't assume an equality comparison for plain COMPARE. + (simplify_comparison): Pass a more accurate code to + make_compound_operation. + 2016-11-07 Pat Haugen <pthaugen@us.ibm.com> * target.def (compute_pressure_classes): New target hook. diff --git a/gcc/combine.c b/gcc/combine.c index f772878..6902056 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -7753,7 +7753,8 @@ extract_left_shift (rtx x, int count) IN_CODE says what kind of expression we are processing. Normally, it is SET. In a memory address it is MEM. When processing the arguments of - a comparison or a COMPARE against zero, it is COMPARE. */ + a comparison or a COMPARE against zero, it is COMPARE, or EQ if more + precisely it is an equality comparison against zero. */ rtx make_compound_operation (rtx x, enum rtx_code in_code) @@ -7767,6 +7768,7 @@ make_compound_operation (rtx x, enum rtx_code in_code) rtx new_rtx = 0; rtx tem; const char *fmt; + bool equality_comparison = false; /* PR rtl-optimization/70944. */ if (VECTOR_MODE_P (mode)) @@ -7776,6 +7778,11 @@ make_compound_operation (rtx x, enum rtx_code in_code) address, we stay there. If we have a comparison, set to COMPARE, but once inside, go back to our default of SET. */ + if (in_code == EQ) + { + equality_comparison = true; + in_code = COMPARE; + } next_code = (code == MEM ? MEM : ((code == COMPARE || COMPARISON_P (x)) && XEXP (x, 1) == const0_rtx) ? COMPARE @@ -7984,11 +7991,12 @@ make_compound_operation (rtx x, enum rtx_code in_code) /* If we are in a comparison and this is an AND with a power of two, convert this into the appropriate bit extract. */ else if (in_code == COMPARE - && (i = exact_log2 (UINTVAL (XEXP (x, 1)))) >= 0) + && (i = exact_log2 (UINTVAL (XEXP (x, 1)))) >= 0 + && (equality_comparison || i < GET_MODE_PRECISION (mode) - 1)) new_rtx = make_extraction (mode, - make_compound_operation (XEXP (x, 0), - next_code), - i, NULL_RTX, 1, 1, 0, 1); + make_compound_operation (XEXP (x, 0), + next_code), + i, NULL_RTX, 1, 1, 0, 1); /* If the one operand is a paradoxical subreg of a register or memory and the constant (limited to the smaller mode) has only zero bits where @@ -12473,7 +12481,11 @@ simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1) We can never remove a SUBREG for a non-equality comparison because the sign bit is in a different place in the underlying object. */ - op0 = make_compound_operation (op0, op1 == const0_rtx ? COMPARE : SET); + rtx_code op0_mco_code = SET; + if (op1 == const0_rtx) + op0_mco_code = code == NE || code == EQ ? EQ : COMPARE; + + op0 = make_compound_operation (op0, op0_mco_code); op1 = make_compound_operation (op1, SET); if (GET_CODE (op0) == SUBREG && subreg_lowpart_p (op0) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 716e6e2..6e12b1a 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-11-07 Bernd Schmidt <bschmidt@redhat.com> + + PR rtl-optimization/77309 + * gcc.dg/torture/pr77309.c: New test. + 2016-11-07 Jakub Jelinek <jakub@redhat.com> PR middle-end/71529 diff --git a/gcc/testsuite/gcc.dg/torture/pr77309.c b/gcc/testsuite/gcc.dg/torture/pr77309.c new file mode 100644 index 0000000..5bdbc0a --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr77309.c @@ -0,0 +1,14 @@ +/* { dg-do run } */ + +int a, b; + +int main () +{ + long c = 1 % (2 ^ b); + c = -c & ~(~(b ^ ~b) || a); + + if (c >= 0) + __builtin_abort (); + + return 0; +} |