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Diffstat (limited to 'mlir/g3doc/Rationale.md')
| -rw-r--r-- | mlir/g3doc/Rationale.md | 40 |
1 files changed, 20 insertions, 20 deletions
diff --git a/mlir/g3doc/Rationale.md b/mlir/g3doc/Rationale.md index 8b22e93598c..949f405d5f6 100644 --- a/mlir/g3doc/Rationale.md +++ b/mlir/g3doc/Rationale.md @@ -150,8 +150,8 @@ func bar(%A : memref<8x?xf32, #lmap>) { // dynamically using dim instruction. %N = dim %A, 1 : memref<8x?xf32, #lmap> - affine.for %i = 0 to 8 { - affine.for %j = 0 to %N { + for %i = 0 to 8 { + for %j = 0 to %N { // A[i,j] += 1 %s1 = load %A [%i, %j] : memref<8x?xf32, #lmap> %s2 = add %s1, 1 @@ -534,7 +534,7 @@ nested in an outer function that using affine loops. func @search(memref<?x?xi32 %A, <?xi32> %S, i32 %key) { %ni = dim %A, 0 : memref<?x?xi32> // This loop can be parallelized - affine.for %i = 0 to %ni { + for %i = 0 to %ni { call @search_body (%A, %S, %i) : (memref<?x?xi32>, memref<?xi32>, i32) } return @@ -568,7 +568,7 @@ func @search_body(%A: memref<?x?xi32>, %S: memref<?xi32>, %key: i32) { As per the [MLIR spec](LangRef.md), the restrictions on dimensions and symbol identifiers to be used with the affine.apply instruction only apply to accesses -inside `affine.for` and `affine.if` instructions. However, an analysis of +inside `for` and `affine.if` instructions. However, an analysis of accesses inside the called function (`@search_body`) is necessary to determine if the `%i` loop could be parallelized: such function access analysis is calling context sensitive. @@ -590,8 +590,8 @@ for (i=0; i <N; i++) ```mlir {.mlir} func @outer_nest(%n) : (i32) { - affine.for %i = 0 to %n { - affine.for %j = 0 to %n { + for %i = 0 to %n { + for %j = 0 to %n { call @inner_nest(%i, %j, %n) } } @@ -606,8 +606,8 @@ func @inner_nest(%i: i32, %j: i32, %n: i32) { } func @inner_nest2(%m, %n) -> i32 { - affine.for %k = 0 to %m { - affine.for %l = 0 to %n { + for %k = 0 to %m { + for %l = 0 to %n { ... } } @@ -649,13 +649,13 @@ in a dilated convolution. func @conv2d(memref<16x1024x1024x3xf32, #lm0, vmem> %input, memref<5x5x3x32xf32, #lm0, vmem> %kernel, memref<16x512x512x32xf32, #lm0, vmem> %output) { - affine.for %b = 0 to %batch { - affine.for %oh = 0 to %output_height { - affine.for %ow = 0 to %output_width { - affine.for %of = 0 to %output_feature { - affine.for %kh = 0 to %kernel_height { - affine.for %kw = 0 to %kernel_width { - affine.for %if = 0 to %input_feature { + for %b = 0 to %batch { + for %oh = 0 to %output_height { + for %ow = 0 to %output_width { + for %of = 0 to %output_feature { + for %kh = 0 to %kernel_height { + for %kw = 0 to %kernel_width { + for %if = 0 to %input_feature { // Calculate input indices. %1_0 = affine.apply #map1_0 (%0#1, %0#2, %0#4, %0#5) [%h_stride, %w_stride, %h_kernel_dilation, %w_kernel_dilation, @@ -899,10 +899,10 @@ func @dma_hbm_to_vmem(memref<1024 x f32, #layout_map0, hbm> %a, representation. 2(b) requires no change, but impacts how cost models look at index and layout maps. -### `affine.if` and `affine.for` Extensions for "Escaping Scalars" {#extensions-for-"escaping-scalars"} +### `affine.if` and `for` Extensions for "Escaping Scalars" {#extensions-for-"escaping-scalars"} We considered providing a representation for SSA values that are live out of -`affine.if/else` conditional bodies and loop carried in `affine.for` loops. We +`affine.if/else` conditional bodies and loop carried in `for` loops. We ultimately abandoned this approach due to its complexity. In the current design of MLIR, scalar variables cannot escape for loops or if instructions. In situations, where escaping is necessary, we use zero-dimensional tensors and @@ -919,7 +919,7 @@ Syntax: ``` {.ebnf} [<out-var-list> =] -affine.for %<index-variable-name> = <lower-bound> ... <upper-bound> step <step> +for %<index-variable-name> = <lower-bound> ... <upper-bound> step <step> [with <in-var-list>] { <loop-instruction-list> } ``` @@ -934,7 +934,7 @@ Example: // Return sum of elements in 1-dimensional mref A func int32 @sum(%A : memref<?xi32>, %N : i32) -> (i32) { %init = 0 - %result = affine.for %i = 0 to N with %tmp(%init) { + %result = for %i = 0 to N with %tmp(%init) { %value = load %A[%i] %sum = %value + %tmp yield %sum @@ -964,7 +964,7 @@ Example: // Compute sum of half of the array func int32 @sum_half(%A, %N) { %s0 = 0 - %s1 = affine.for %i = 1 ... N step 1 with %s2 (%s0) { + %s1 = for %i = 1 ... N step 1 with %s2 (%s0) { %s3 = affine.if (%i >= %N / 2) { %v0 = load %A[%i] %s4 = %s2 + %v0 |
