Philipp Tomsich 018e96f71f [RISCV] Add isel-patterns to optimize (a < 1) into blez (a <= 0) ...

The following code-sequence showed up in a testcase (isolated from
SPEC2017) for if-conversion and vectorization when searching for the
maximum in an array:
        addi    a2, zero, 1
        blt     a1, a2, .LBB0_5
which can be expressed as `bge zero,a1,.LBB0_5`/`blez a1,/LBB0_5`.

More generally, we want to express (a < 1) as (a <= 0).

This adds the required isel-pattern and updates the testcases.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D98449

2021-03-15 11:32:43 -07:00

3.5 KiB

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