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remove two implemented items

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26728 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
2006-03-13 06:52:22 +00:00
parent 947c28935d
commit 2e8a77ff42
1 changed files with 0 additions and 22 deletions
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22
lib/Target/README.txt
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@@ -56,20 +56,6 @@ Number 1 is the preferred solution.
//===---------------------------------------------------------------------===// //===---------------------------------------------------------------------===//
DAG combine this into mul A, 8:
int %test(int %A) {
%B = mul int %A, 8 ;; shift
%C = add int %B, 7 ;; dead, no demanded bits.
%D = and int %C, -8 ;; dead once add is gone.
ret int %D
}
This sort of thing occurs in the alloca lowering code and other places that
are generating alignment of an already aligned value.
//===---------------------------------------------------------------------===//
Turn this into a signed shift right in instcombine: Turn this into a signed shift right in instcombine:
int f(unsigned x) { int f(unsigned x) {
@@ -81,14 +67,6 @@ http://gcc.gnu.org/ml/gcc-patches/2006-02/msg01492.html
//===---------------------------------------------------------------------===// //===---------------------------------------------------------------------===//
We should reassociate:
int f(int a, int b){ return a * a + 2 * a * b + b * b; }
into:
int f(int a, int b) { return a * (a + 2 * b) + b * b; }
to eliminate a multiply.
//===---------------------------------------------------------------------===//
On targets with expensive 64-bit multiply, we could LSR this: On targets with expensive 64-bit multiply, we could LSR this:
for (i = ...; ++i) { for (i = ...; ++i) {