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| author | Roger Sayle <roger@eyesopen.com> | 2003-08-04 23:42:48 +0000 |
|---|---|---|
| committer | Roger Sayle <sayle@gcc.gnu.org> | 2003-08-04 23:42:48 +0000 |
| commit | f2593a6649384b002184762c58b083eb5f8e939f (patch) | |
| tree | 9617a20782252283684d9c8639c9ad8e7fbf7873 /gcc/expmed.c | |
| parent | 29019803327d246f686bcc22d9d95b0e3cdc244d (diff) | |
| download | gcc-f2593a6649384b002184762c58b083eb5f8e939f.zip gcc-f2593a6649384b002184762c58b083eb5f8e939f.tar.gz gcc-f2593a6649384b002184762c58b083eb5f8e939f.tar.bz2 | |
fold-const.c (fold <PLUS_EXPR>): Transform x+x into x*2.0.
* fold-const.c (fold <PLUS_EXPR>): Transform x+x into x*2.0.
Optimize x*c+x and x+x*c into x*(c+1) and x*c1+x*c2 into x*(c1+c2)
for floating point expressions with -ffast-math.
(fold <MULT_EXPR>): Don't transform x*2.0 into x+x.
* expmed.c (expand_mult): Wrap long line. Expand x*2.0 as x+x.
* gcc.dg/20030804-1.c: New test case.
From-SVN: r70158
Diffstat (limited to 'gcc/expmed.c')
| -rw-r--r-- | gcc/expmed.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/gcc/expmed.c b/gcc/expmed.c index 68163e9..89ecd0c 100644 --- a/gcc/expmed.c +++ b/gcc/expmed.c @@ -2300,7 +2300,8 @@ synth_mult (struct algorithm *alg_out, unsigned HOST_WIDE_INT t, you should swap the two operands if OP0 would be constant. */ rtx -expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target, int unsignedp) +expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target, + int unsignedp) { rtx const_op1 = op1; @@ -2514,6 +2515,28 @@ expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target, int unsignedp } } + if (GET_CODE (op0) == CONST_DOUBLE) + { + rtx temp = op0; + op0 = op1; + op1 = temp; + } + + /* Expand x*2.0 as x+x. */ + if (GET_CODE (op1) == CONST_DOUBLE + && GET_MODE_CLASS (mode) == MODE_FLOAT) + { + REAL_VALUE_TYPE d; + REAL_VALUE_FROM_CONST_DOUBLE (d, op1); + + if (REAL_VALUES_EQUAL (d, dconst2)) + { + op0 = force_reg (GET_MODE (op0), op0); + return expand_binop (mode, add_optab, op0, op0, + target, unsignedp, OPTAB_LIB_WIDEN); + } + } + /* This used to use umul_optab if unsigned, but for non-widening multiply there is no difference between signed and unsigned. */ op0 = expand_binop (mode, |