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| author | kenner <kenner@138bc75d-0d04-0410-961f-82ee72b054a4> | 1994-11-29 21:49:53 +0000 |
|---|---|---|
| committer | kenner <kenner@138bc75d-0d04-0410-961f-82ee72b054a4> | 1994-11-29 21:49:53 +0000 |
| commit | c2c10df65751c8ce7d479f864432444eaa6e6248 (patch) | |
| tree | 907bd6ed7ca613bf2d54f47b032209ebe8f67404 /gcc/expmed.c | |
| parent | 883e35f42c0d0e344e546d2e8deafc9acabae842 (diff) | |
| download | gcc-c2c10df65751c8ce7d479f864432444eaa6e6248.tar.gz | |
(expand_shift): Open-code rotate even if by a variable.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@8579 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/expmed.c')
| -rw-r--r-- | gcc/expmed.c | 41 |
1 files changed, 20 insertions, 21 deletions
diff --git a/gcc/expmed.c b/gcc/expmed.c index 900c2e671ff..92ac24c9ac7 100644 --- a/gcc/expmed.c +++ b/gcc/expmed.c @@ -1682,8 +1682,7 @@ expand_shift (code, mode, shifted, amount, target, unsignedp) continue; else if (methods == OPTAB_LIB_WIDEN) { - /* If we are rotating by a constant that is valid and - we have been unable to open-code this by a rotation, + /* If we have been unable to open-code this by a rotation, do it as the IOR of two shifts. I.e., to rotate A by N bits, compute (A << N) | ((unsigned) A >> (C - N)) where C is the bitsize of A. @@ -1695,25 +1694,25 @@ expand_shift (code, mode, shifted, amount, target, unsignedp) this extremely unlikely lossage to avoid complicating the code below. */ - if (GET_CODE (op1) == CONST_INT && INTVAL (op1) > 0 - && INTVAL (op1) < GET_MODE_BITSIZE (mode)) - { - rtx subtarget = target == shifted ? 0 : target; - rtx temp1; - tree other_amount - = build_int_2 (GET_MODE_BITSIZE (mode) - INTVAL (op1), 0); - - shifted = force_reg (mode, shifted); - - temp = expand_shift (left ? LSHIFT_EXPR : RSHIFT_EXPR, - mode, shifted, amount, subtarget, 1); - temp1 = expand_shift (left ? RSHIFT_EXPR : LSHIFT_EXPR, - mode, shifted, other_amount, 0, 1); - return expand_binop (mode, ior_optab, temp, temp1, target, - unsignedp, methods); - } - else - methods = OPTAB_LIB; + rtx subtarget = target == shifted ? 0 : target; + rtx temp1; + tree type = TREE_TYPE (amount); + tree new_amount = make_tree (type, op1); + tree other_amount + = fold (build (MINUS_EXPR, type, + convert (type, + build_int_2 (GET_MODE_BITSIZE (mode), + 0)), + amount)); + + shifted = force_reg (mode, shifted); + + temp = expand_shift (left ? LSHIFT_EXPR : RSHIFT_EXPR, + mode, shifted, new_amount, subtarget, 1); + temp1 = expand_shift (left ? RSHIFT_EXPR : LSHIFT_EXPR, + mode, shifted, other_amount, 0, 1); + return expand_binop (mode, ior_optab, temp, temp1, target, + unsignedp, methods); } temp = expand_binop (mode, |