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| author | Roger Sayle <roger@eyesopen.com> | 2006-05-29 16:22:05 +0000 |
|---|---|---|
| committer | Roger Sayle <sayle@gcc.gnu.org> | 2006-05-29 16:22:05 +0000 |
| commit | 1753331b5bb8a14b709916450c93c98c2e2a007b (patch) | |
| tree | 978c2831d92b849c43dacb024987911ecab7ea4d /gcc/simplify-rtx.c | |
| parent | 06ac89d1ca5a07462804d35fff86331f9f61eae4 (diff) | |
| download | gcc-1753331b5bb8a14b709916450c93c98c2e2a007b.zip gcc-1753331b5bb8a14b709916450c93c98c2e2a007b.tar.gz gcc-1753331b5bb8a14b709916450c93c98c2e2a007b.tar.bz2 | |
re PR tree-optimization/24964 (Does not optimise abs(x)**2 to x**2)
PR tree-optimization/24964
* simplify-rtx.c (simplify_binary_operation_1): Add function comment.
<MULT>: Minor clean-up. Don't convert x*-1.0 into -x if we honor
signaling NaNs. Optimize -x*-x as x*x for all float modes, and
abs(x)*abs(x) as x*x for scalar floating point modes.
* gcc.target/i386/387-10.c: New test case.
From-SVN: r114206
Diffstat (limited to 'gcc/simplify-rtx.c')
| -rw-r--r-- | gcc/simplify-rtx.c | 36 |
1 files changed, 29 insertions, 7 deletions
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index 7199316..c51ca9e 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -1472,6 +1472,11 @@ simplify_binary_operation (enum rtx_code code, enum machine_mode mode, return simplify_binary_operation_1 (code, mode, op0, op1, trueop0, trueop1); } +/* Subroutine of simplify_binary_operation. Simplify a binary operation + CODE with result mode MODE, operating on OP0 and OP1. If OP0 and/or + OP1 are constant pool references, TRUEOP0 and TRUEOP1 represent the + actual constants. */ + static rtx simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode, rtx op0, rtx op1, rtx trueop0, rtx trueop1) @@ -1907,12 +1912,12 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode, return simplify_gen_binary (ASHIFT, mode, op0, GEN_INT (val)); /* Likewise for multipliers wider than a word. */ - else if (GET_CODE (trueop1) == CONST_DOUBLE - && (GET_MODE (trueop1) == VOIDmode - || GET_MODE_CLASS (GET_MODE (trueop1)) == MODE_INT) - && GET_MODE (op0) == mode - && CONST_DOUBLE_LOW (trueop1) == 0 - && (val = exact_log2 (CONST_DOUBLE_HIGH (trueop1))) >= 0) + if (GET_CODE (trueop1) == CONST_DOUBLE + && (GET_MODE (trueop1) == VOIDmode + || GET_MODE_CLASS (GET_MODE (trueop1)) == MODE_INT) + && GET_MODE (op0) == mode + && CONST_DOUBLE_LOW (trueop1) == 0 + && (val = exact_log2 (CONST_DOUBLE_HIGH (trueop1))) >= 0) return simplify_gen_binary (ASHIFT, mode, op0, GEN_INT (val + HOST_BITS_PER_WIDE_INT)); @@ -1927,10 +1932,27 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode, if (REAL_VALUES_EQUAL (d, dconst2)) return simplify_gen_binary (PLUS, mode, op0, copy_rtx (op0)); - if (REAL_VALUES_EQUAL (d, dconstm1)) + if (!HONOR_SNANS (mode) + && REAL_VALUES_EQUAL (d, dconstm1)) return simplify_gen_unary (NEG, mode, op0, mode); } + /* Optimize -x * -x as x * x. */ + if (FLOAT_MODE_P (mode) + && GET_CODE (op0) == NEG + && GET_CODE (op1) == NEG + && rtx_equal_p (XEXP (op0, 0), XEXP (op1, 0)) + && !side_effects_p (XEXP (op0, 0))) + return simplify_gen_binary (MULT, mode, XEXP (op0, 0), XEXP (op1, 0)); + + /* Likewise, optimize abs(x) * abs(x) as x * x. */ + if (SCALAR_FLOAT_MODE_P (mode) + && GET_CODE (op0) == ABS + && GET_CODE (op1) == ABS + && rtx_equal_p (XEXP (op0, 0), XEXP (op1, 0)) + && !side_effects_p (XEXP (op0, 0))) + return simplify_gen_binary (MULT, mode, XEXP (op0, 0), XEXP (op1, 0)); + /* Reassociate multiplication, but for floating point MULTs only when the user specifies unsafe math optimizations. */ if (! FLOAT_MODE_P (mode) |