Change Details

In fast-math mode, in some cases a DAG like (fadd (fma (a, b, ... (fma (c, d, (fmul (e, f)))))), g) can occur (for instance, when combining several fadds and fmuls into fma instructions), but being left with an outermost fadd and an innermost fmul, this sequence can be transformed into (fadd (fma (a, b, ... (fma (c, d, g)))), (fmul (e, f)) which swaps the solidary operand from the fadd with the innermost fmul. This allows for generating even more fma instructions.

This patch changes a FADD / FMUL => FMA ISel pattern implemented in D80801 so that it peeks through more than one FMA. This also changes the order of the operands, which can help with eliminating a final COPY.

In fast-math mode, in some cases a DAG like (fadd (fma (a, b, ... (fma (c, d, (fmul (e, f)))))), g) can occur (for instance, when combining several fadds and fmulsThis patch changes a FADD / FMUL => FMA ISel pattern implemented into fma instructions), but being left with an outermost fadd and an innermost fmul, this sequence can be transformed into (fadd (fma (a, b, ... (fma (c, d, g)))), (fmul (e, D80801 so that it peeks through more than one FMA. f)) which swaps the solidary operand from the fadd with theThis also innermost fmul.changes the order of the operands, This allows for generating even more fma instructionswhich can help with eliminating a final COPY.