llvm-project

9a42e5ba - [mlir][tosa] Remove 'Pure' trait from operations that are not speculatable (#185700)

[mlir][tosa] Remove 'Pure' trait from operations that are not speculatable (#185700) This commit removes the 'Pure' trait from a number of TOSA operations. Instead of marking most ops as pure by default, the trait is now opt-in for operations that are provably side-effect free and speculatable. Several operations were previously marked as pure unintentionally. The following operations have had 'Pure' removed (reason in brackets): - ARGMAX (out-of-range index) - AVG_POOL2D (accumulator overflow/underflow) - AVG_POOL2D_ADAPTIVE (same as above) - CONV2D (accumulator overflow/underflow) - CONV2D_BLOCK_SCALED (accumulator overflow/underflow) - CONV3D (accumulator overflow/underflow) - DEPTHWISE_CONV2D (accumulator overflow/underflow) - MATMUL (accumulator overflow/underflow) - MATMUL_T_BLOCK_SCALED (accumulator overflow/underflow) - TRANSPOSE_CONV2D (accumulator overflow/underflow) - ADD (overflow) - SUB (underflow) - MUL (invalid shift, overflow) - ARITHMETIC_RIGHT_SHIFT (invalid shift value) - LOGICAL_LEFT_SHIFT (invalid shift value) - LOGICAL_RIGHT_SHIFT (invalid shift value) - INTDIV (division by zero) - POW (negative exponent restrictions) - TABLE (invalid slope computation) - ABS (underflow) - NEGATE (overflow/underflow) - REDUCE_PRODUCT (overflow) - REDUCE_SUM (overflow) - GATHER (out-of-range indices) - SCATTER (out-of-range or duplicate indices) - RESCALE (overflow/underflow) Many of these operations can exhibit undefined behaviour when a `REQUIRE` condition in the TOSA specification pseudocode fails. Whether such failures result in a runtime error is implementation-defined. As a result, speculating or reordering these operations can change program behaviour. For this reason, the `AlwaysSpeculatable` property implied by `Pure` is not valid for these ops. The `NoMemoryEffect` trait is retained, as these operations do not have direct memory side effects.