diff options
| author | Jakub Jelinek <jakub@gcc.gnu.org> | 2017-12-08 00:56:34 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2017-12-08 00:56:34 +0100 |
| commit | 7f5aed1e5d7b8f02ed81178f65d84cbd27ec88cd (patch) | |
| tree | 19a103430578ba4a53e3f95d98e6a0aa9aa7770d /gcc/config | |
| parent | 9b6c97373a0ca04b5888a1c4ca6519c94388da50 (diff) | |
| download | gcc-7f5aed1e5d7b8f02ed81178f65d84cbd27ec88cd.zip gcc-7f5aed1e5d7b8f02ed81178f65d84cbd27ec88cd.tar.gz gcc-7f5aed1e5d7b8f02ed81178f65d84cbd27ec88cd.tar.bz2 | |
re PR target/81906 (Calls to rint() wrongly optimized away starting in g++ 6)
PR target/81906
* config/i386/i386.c (ix86_expand_rint): Handle flag_rounding_math.
* gcc.target/i386/pr81906.c: New test.
From-SVN: r255486
Diffstat (limited to 'gcc/config')
| -rw-r--r-- | gcc/config/i386/i386.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 5d77f28..e323102 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -44255,8 +44255,7 @@ ix86_expand_lfloorceil (rtx op0, rtx op1, bool do_floor) emit_move_insn (op0, ireg); } -/* Expand rint (IEEE round to nearest) rounding OPERAND1 and storing the - result in OPERAND0. */ +/* Expand rint rounding OPERAND1 and storing the result in OPERAND0. */ void ix86_expand_rint (rtx operand0, rtx operand1) { @@ -44264,11 +44263,17 @@ ix86_expand_rint (rtx operand0, rtx operand1) xa = fabs (operand1); if (!isless (xa, 2**52)) return operand1; - xa = xa + 2**52 - 2**52; + two52 = 2**52; + if (flag_rounding_math) + { + two52 = copysign (two52, operand1); + xa = operand1; + } + xa = xa + two52 - two52; return copysign (xa, operand1); */ machine_mode mode = GET_MODE (operand0); - rtx res, xa, TWO52, mask; + rtx res, xa, TWO52, two52, mask; rtx_code_label *label; res = gen_reg_rtx (mode); @@ -44281,8 +44286,16 @@ ix86_expand_rint (rtx operand0, rtx operand1) TWO52 = ix86_gen_TWO52 (mode); label = ix86_expand_sse_compare_and_jump (UNLE, TWO52, xa, false); - xa = expand_simple_binop (mode, PLUS, xa, TWO52, NULL_RTX, 0, OPTAB_DIRECT); - xa = expand_simple_binop (mode, MINUS, xa, TWO52, xa, 0, OPTAB_DIRECT); + two52 = TWO52; + if (flag_rounding_math) + { + two52 = gen_reg_rtx (mode); + ix86_sse_copysign_to_positive (two52, TWO52, res, mask); + xa = res; + } + + xa = expand_simple_binop (mode, PLUS, xa, two52, NULL_RTX, 0, OPTAB_DIRECT); + xa = expand_simple_binop (mode, MINUS, xa, two52, xa, 0, OPTAB_DIRECT); ix86_sse_copysign_to_positive (res, xa, res, mask); |