llvm-project

3502d340 - [flang] Adjust transformational folding to match runtime (#90132)

[flang] Adjust transformational folding to match runtime (#90132) The transformational intrinsic functions MATMUL, DOT_PRODUCT, and NORM2 all involve summing up intermediate products into accumulators. In the constant folding library, this is done with extended precision Kahan summation for REAL and COMPLEX arguments, but in the runtime implementations it is not, and this leads to discrepancies between folded results and dynamic results. Disable the use of Kahan summation in folding to resolve these discrepancies, but don't discard the code, in case we want to add Kahan summation in the runtime for some or all of these intrinsic functions.