From d356f84d4ceb9fb63e4b254ab8b26ce891c2f2b9 Mon Sep 17 00:00:00 2001 From: Connor Abbott Date: Tue, 21 Jul 2015 19:54:32 -0700 Subject: [PATCH] nir/cf: add split_block_cursor() This is a helper that will be shared between the new control flow insertion and modification code. Signed-off-by: Connor Abbott Reviewed-by: Kenneth Graunke --- src/glsl/nir/nir_control_flow.c | 48 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/src/glsl/nir/nir_control_flow.c b/src/glsl/nir/nir_control_flow.c index fcdabc7..935ec9f 100644 --- a/src/glsl/nir/nir_control_flow.c +++ b/src/glsl/nir/nir_control_flow.c @@ -394,6 +394,54 @@ split_block_before_instr(nir_instr *instr) return new_block; } +/* Splits a basic block at the point specified by the cursor. The "before" and + * "after" arguments are filled out with the blocks resulting from the split + * if non-NULL. Note that the "beginning" of the block is actually interpreted + * as before the first non-phi instruction, and it's illegal to split a block + * before a phi instruction. + */ + +static void +split_block_cursor(nir_cursor cursor, + nir_block **_before, nir_block **_after) +{ + nir_block *before, *after; + switch (cursor.option) { + case nir_cursor_before_block: + after = cursor.block; + before = split_block_beginning(cursor.block); + break; + + case nir_cursor_after_block: + before = cursor.block; + after = split_block_end(cursor.block); + break; + + case nir_cursor_before_instr: + after = cursor.instr->block; + before = split_block_before_instr(cursor.instr); + break; + + case nir_cursor_after_instr: + /* We lower this to split_block_before_instr() so that we can keep the + * after-a-jump-instr case contained to split_block_end(). + */ + if (nir_instr_is_last(cursor.instr)) { + before = cursor.instr->block; + after = split_block_end(cursor.instr->block); + } else { + after = cursor.instr->block; + before = split_block_before_instr(nir_instr_next(cursor.instr)); + } + break; + } + + if (_before) + *_before = before; + if (_after) + *_after = after; +} + /** * Inserts a non-basic block between two basic blocks and links them together. */ -- 2.7.4