This reverts r334428. It incorrectly marks some multiplications as nuw. Tim
Shen is working on a proper fix.
Original commit message:
[SCEV] Add nuw/nsw to mul ops in StrengthenNoWrapFlags where safe.
Summary:
Previously we would add them for adds, but not multiplies.
llvm-svn: 335016
IndVarSimplify sometimes makes transforms basing on users that are trivially dead. In particular,
if DCE wasn't run before it, there may be a dead `sext/zext` in loop that will trigger widening
transforms, however it makes no sense to do it.
This patch teaches IndVarsSimplify ignore the mist trivial cases of that.
Differential Revision: https://reviews.llvm.org/D47974
Reviewed By: sanjoy
llvm-svn: 334567
Summary:
Previously we would add them for adds, but not multiplies.
Reviewers: sanjoy
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D48038
llvm-svn: 334428
My commit rL216160 introduced a bug PR21014: IndVars widens code 'for (i = ; i < ...; i++) arr[ CONST - i]' into 'for (i = ; i < ...; i++) arr[ i - CONST]'
thus inverting index expression. This patch fixes it.
Thanks to Jörg Sonnenberger for pointing.
Differential Revision: http://reviews.llvm.org/D5576
llvm-svn: 218867
Currently only "add nsw" are widened. This patch eliminates tons of "sext" instructions for 64 bit code (and the corresponding target code) in cases like:
int N = 100;
float **A;
void foo(int x0, int x1)
{
float * A_cur = &A[0][0];
float * A_next = &A[1][0];
for(int x = x0; x < x1; ++x).
{
// Currently only [x+N] case is widened. Others 2 cases lead to sext.
// This patch fixes it, so all 3 cases do not need sext.
const float div = A_cur[x + N] + A_cur[x - N] + A_cur[x * N];
A_next[x] = div;
}
}
...
> clang++ test.cpp -march=core-avx2 -Ofast -fno-unroll-loops -fno-tree-vectorize -S -o -
Differential Revision: http://reviews.llvm.org/D4695
llvm-svn: 216160
Sanjoy Das