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* glsl: Fix unroll of do{} while(false) like loopsDanylo Piliaiev2019-09-061-11/+4
| | | | | | | | | | | | | | | For loops which condition is false on the first iteration iteration count was falsely calculated under the assumption that loop's condition is true until it becomes false, meaning it's true at least one time. Now such loops are reported as having 0 iteration. Similar to the fix e71fc7f2 done in NIR. Fixes tests/shaders/glsl-fs-loop-while-false-02.shader_test Signed-off-by: Danylo Piliaiev <[email protected]> Reviewed-by: Timothy Arceri <[email protected]>
* glsl: Don't increase the iteration count when there are no terminatorsIan Romanick2019-06-241-1/+7
| | | | | | | | | | | | | | | | | | | Incrementing the iteration count was intended to fix an off-by-one error when the first terminator was superseded by a later terminator. If there is no first terminator or later terminator, there is no off-by-one error. Incrementing the loop count creates one. This can be seen in loops like: do { if (something) { // No breaks or continues here. } } while (false); Reviewed-by: Timothy Arceri <[email protected]> Tested-by: Abel Briggs <[email protected]> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110953 Fixes: 646621c66da ("glsl: make loop unrolling more like the nir unrolling path")
* glsl: remove unreachable assert()Emil Velikov2018-04-101-2/+0
| | | | | | | | | | Earlier commit enforced that we'll bail out if the number of terminators is different than 2. With that in mind, the assert() will never trigger. Fixes: 56b867395de ("glsl: fix infinite loop caused by bug in loop unrolling pass") Reviewed-by: Timothy Arceri <[email protected]> Signed-off-by: Emil Velikov <[email protected]>
* glsl: fix infinite loop caused by bug in loop unrolling passTimothy Arceri2018-03-271-1/+1
| | | | | | | | | | | | | | | | | | Just checking for 2 jumps is not enough to be sure we can do a complex loop unroll. We need to make sure we also have also found 2 loop terminators. Without this we were attempting to unroll a loop where the second jump was nested inside multiple ifs which loop analysis is unable to detect as a terminator. We ended up splicing out the first terminator but failed to actually unroll the loop, this resulted in the creation of a possible infinite loop. Fixes: 646621c66da9 "glsl: make loop unrolling more like the nir unrolling path" Tested-by: Gert Wollny <[email protected]> Reviewed-by: Ian Romanick <[email protected]> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105670
* glsl: make loop unrolling more like the nir unrolling pathTimothy Arceri2017-10-101-38/+134
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The old code assumed that loop terminators will always be at the start of the loop, resulting in otherwise unrollable loops not being unrolled at all. For example the current code would unroll: int j = 0; do { if (j > 5) break; ... do stuff ... j++; } while (j < 4); But would fail to unroll the following as no iteration limit was calculated because it failed to find the terminator: int j = 0; do { ... do stuff ... j++; } while (j < 4); Also we would fail to unroll the following as we ended up calculating the iteration limit as 6 rather than 4. The unroll code then assumed we had 3 terminators rather the 2 as it wasn't able to determine that "if (j > 5)" was redundant. int j = 0; do { if (j > 5) break; ... do stuff ... if (bool(i)) break; j++; } while (j < 4); This patch changes this pass to be more like the NIR unrolling pass. With this change we handle loop terminators correctly and also handle cases where the terminators have instructions in their branches other than a break. V2: - fixed regression where loops with a break in else were never unrolled in v1. - fixed confusing/wrong naming of bools in complex unrolling. Reviewed-by: Nicolai Hähnle <[email protected]> Tested-by: Dieter Nützel <[email protected]>
* glsl: don't drop instructions from unreachable terminators continue branchTimothy Arceri2017-10-101-8/+20
| | | | | | | | | | | | | These instructions will be executed on every iteration of the loop we cannot drop them. V2: - move removal of unreachable terminators from the terminator list to the same place they are removed from the IR as suggested by Nicolai. Reviewed-by: Nicolai Hähnle <[email protected]> Tested-by: Dieter Nützel <[email protected]>
* glsl: merge loop_controls.cpp with loop_unroll.cppTimothy Arceri2017-09-211-2/+34
| | | | | | | Having this separate just makes the code harder to follow, and requires an extra walk of the IR. Reviewed-by: Thomas Helland <[email protected]>
* glsl: pass mem_ctx to constant_expression_value(...) and friendsTimothy Arceri2017-08-111-1/+1
| | | | | | | | | | | | | | | | | | | | The main motivation for this is that threaded compilation can fall over if we were to allocate IR inside constant_expression_value() when calling it on a builtin. This is because builtins are shared across the whole OpenGL context. f81ede469910d worked around the problem by cloning the entire builtin before constant_expression_value() could be called on it. However cloning the whole function each time we referenced it lead to a significant reduction in the GLSL IR compiler performance. This change along with the following patch helps fix that performance regression. Other advantages are that we reduce the number of calls to ralloc_parent(), and for loop unrolling we free constants after they are used rather than leaving them hanging around. Reviewed-by: Kenneth Graunke <[email protected]>
* glsl: Detect do-while-false loops and unroll themIan Romanick2016-02-241-4/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously loops like do { // ... } while (false); that did not have any other loop-branch instructions would not be unrolled. This is commonly used to wrap multiline preprocessor macros. This produces IR like (loop ( ... break )) Since limiting_terminator was NULL, the loop unroller would throw up its hands and say, "I don't know how many iterations. How can I unroll this?" We can detect this another way. If there is no limiting_terminator and the only loop-branch is a break as the last IR, there's only one iteration. On my very old checkout of shader-db, this removes a loop from Orbital Explorer, but it does not otherwise affect the shader. The loop removed is the one the compiler inserts surrounding the switch statement. This change does prevent some seriously bad code generation in some patches to meta shaders that I recently sent out for review. Signed-off-by: Ian Romanick <[email protected]> Reviewed-by: Timothy Arceri <[email protected]>
* glsl: move to compiler/Emil Velikov2016-01-261-0/+432
Signed-off-by: Emil Velikov <[email protected]> Acked-by: Matt Turner <[email protected]> Acked-by: Jose Fonseca <[email protected]>