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| author | Richard Stallman <rms@gnu.org> | 1993-01-09 08:51:21 +0000 |
|---|---|---|
| committer | Richard Stallman <rms@gnu.org> | 1993-01-09 08:51:21 +0000 |
| commit | 96f153da76ef81ea180b17b192f4603710b86c83 (patch) | |
| tree | f0f7a06c5b9716367d11471ab72f223a924e5685 /gcc/optabs.c | |
| parent | 676ce2231660dc6ef0272e7af463f4f24733082d (diff) | |
| download | gcc-96f153da76ef81ea180b17b192f4603710b86c83.zip gcc-96f153da76ef81ea180b17b192f4603710b86c83.tar.gz gcc-96f153da76ef81ea180b17b192f4603710b86c83.tar.bz2 | |
(expand_binop): For complex mult, compute res in each alternative, not before.
From-SVN: r3165
Diffstat (limited to 'gcc/optabs.c')
| -rw-r--r-- | gcc/optabs.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/gcc/optabs.c b/gcc/optabs.c index a629513..f46f459 100644 --- a/gcc/optabs.c +++ b/gcc/optabs.c @@ -889,7 +889,9 @@ expand_binop (mode, binoptab, op0, op1, target, unsignedp, methods) switch (binoptab->code) { case PLUS: + /* (a+ib) + (c+id) = (a+c) + i(b+d) */ case MINUS: + /* (a+ib) - (c+id) = (a-c) + i(b-d) */ res = expand_binop (submode, binoptab, real0, real1, realr, unsignedp, methods); if (res != realr) @@ -912,15 +914,14 @@ expand_binop (mode, binoptab, op0, op1, target, unsignedp, methods) case MULT: /* (a+ib) * (c+id) = (ac-bd) + i(ad+cb) */ - res = expand_binop (submode, binoptab, real0, real1, - realr, unsignedp, methods); - if (imag0 && imag1) { rtx temp = - expand_binop (submode, sub_optab, res, - expand_binop (submode, binoptab, imag0, imag1, - 0, unsignedp, methods), + expand_binop (submode, sub_optab, + expand_binop (submode, binoptab, real0, + real1, 0, unsignedp, methods), + expand_binop (submode, binoptab, imag0, + imag1, 0, unsignedp, methods), realr, unsignedp, methods); if (temp != realr) @@ -939,6 +940,8 @@ expand_binop (mode, binoptab, op0, op1, target, unsignedp, methods) } else { + res = expand_binop (submode, binoptab, real0, real1, + realr, unsignedp, methods); if (res != realr) emit_move_insn (realr, res); @@ -954,11 +957,11 @@ expand_binop (mode, binoptab, op0, op1, target, unsignedp, methods) break; case DIV: - /* (c+id)/(a+ib) == ((c+id)*(a-ib))/(a*a+b*b) */ + /* (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd)) */ if (! imag1) - { - /* Simply divide the real and imaginary parts by `a' */ + { /* (a+ib) / (c+i0) = (a/c) + i(b/c) */ + /* Simply divide the real and imaginary parts by `c' */ res = expand_binop (submode, binoptab, real0, real1, realr, unsignedp, methods); if (res != realr) |