tree d61da121c8f0a97facbe46c74005176290a13cb2
parent fe3f01367f8071e6125ddff212d39b5b17f83e25
author Ben Clayton <bclayton@google.com> 1553789220 +0000
committer Ben Clayton <bclayton@google.com> 1553891324 +0000

SpirvShader: Fixes for complex loops.

Emit loops in forward direction. While traversing backwards from the loop back-edge means you don't have to worry about flowing down the merge block, it can lead to blocks being generated in orders that can break the visit-once logic.

Don't consider flows passing through the return block as a back edge.

Strip unreachable blocks from ins - nothing should ever consider them.

Tests: dEQP-VK.glsl.loops.*
Bug: b/128527271
Change-Id: I497a06f5ce65d54b39294e4016b2df6d2c70487c
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/28188
Tested-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>