[spirv-reader] Refine selection construct concept
Distinguish between selections constructs starting with with
OpBranchConditional and those starting with OpSwitch.
We'll use this in a followup CL to track break from a switch.
Bug: tint:3
Change-Id: I8d000cb42325535a4937c84f83a83c98a9b8d4c5
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/21080
Reviewed-by: dan sinclair <dsinclair@google.com>
diff --git a/src/reader/spirv/construct.h b/src/reader/spirv/construct.h
index f458868..a63437d 100644
--- a/src/reader/spirv/construct.h
+++ b/src/reader/spirv/construct.h
@@ -31,10 +31,16 @@
struct Construct {
/// Enumeration for the kinds of structured constructs.
enum Kind {
- kFunction, // The whole function.
- kSelection, // A SPIR-V selection construct
- kLoop, // A SPIR-V loop construct
- kContinue, // A SPIR-V continue construct
+ /// The whole function.
+ kFunction,
+ /// A SPIR-V selection construct, header ending in OpBrancConditional
+ kIfSelection,
+ /// A SPIR-V selection construct, header ending in OpSwitch
+ kSwitchSelection,
+ /// A SPIR-V loop construct
+ kLoop,
+ /// A SPIR-V continue construct
+ kContinue,
};
/// Constructor
@@ -94,8 +100,10 @@
switch (kind) {
case Construct::kFunction:
return "Function";
- case Construct::kSelection:
- return "Selection";
+ case Construct::kIfSelection:
+ return "IfSelection";
+ case Construct::kSwitchSelection:
+ return "SwitchSelection";
case Construct::kLoop:
return "Loop";
case Construct::kContinue:
diff --git a/src/reader/spirv/function.cc b/src/reader/spirv/function.cc
index 7d23923..0c20f73 100644
--- a/src/reader/spirv/function.cc
+++ b/src/reader/spirv/function.cc
@@ -791,7 +791,12 @@
// From the interval rule, the selection construct consists of blocks
// in the block order, starting at the header, until just before the
// merge block.
- top = push_construct(depth, Construct::kSelection, header, merge);
+ const auto branch_opcode =
+ header_info->basic_block->terminator()->opcode();
+ const auto kind = (branch_opcode == SpvOpBranchConditional)
+ ? Construct::kIfSelection
+ : Construct::kSwitchSelection;
+ top = push_construct(depth, kind, header, merge);
}
}
@@ -819,14 +824,11 @@
return false;
}
for (auto& construct : constructs_) {
- if (construct->kind != Construct::kSelection) {
+ if (construct->kind != Construct::kSwitchSelection) {
continue;
}
const auto* branch =
GetBlockInfo(construct->begin_id)->basic_block->terminator();
- if (branch->opcode() != SpvOpSwitch) {
- continue;
- }
// Mark the default block
const auto default_id = branch->GetSingleWordInOperand(1);
diff --git a/src/reader/spirv/function.h b/src/reader/spirv/function.h
index e5bf677..72fb2ab 100644
--- a/src/reader/spirv/function.h
+++ b/src/reader/spirv/function.h
@@ -43,17 +43,24 @@
// A back-edge: An edge from a node to one of its ancestors in a depth-first
// search from the entry block.
kBack,
- // An edge from a node to the merge block of the nearest enclosing structured
- // construct. We write "ToMerge" to make it clear the destination block is
- // the merge block, not the source block.
- kToMerge,
- // An edge from a node to the merge block of the nearest enclosing loop.
+ // An edge from a node to the merge block of the nearest enclosing switch,
+ // where there is no intervening loop.
+ kSwitchBreak,
+ // An edge from a node to the merge block of the nearest enclosing loop, where
+ // there is no intervening switch.
// The source block is a "break block" as defined by SPIR-V.
kLoopBreak,
// An edge from a node in a loop body to the associated continue target, where
// there are no other intervening loops or switches.
// The source block is a "continue block" as defined by SPIR-V.
kLoopContinue,
+ // An edge from a node to the merge block of the nearest enclosing structured
+ // construct, but which is neither a kSwitchBreak or a kLoopBreak.
+ // This can only occur for an "if" selection, i.e. where the selection
+ // header ends in OpBranchConditional.
+ // TODO(dneto): Rename this to kIfBreak after we correctly classify edges
+ // as kSwitchBreak.
+ kToMerge,
// An edge from one switch case to the next sibling switch case.
kCaseFallThrough,
// None of the above. By structured control flow rules, there can be at most
diff --git a/src/reader/spirv/function_cfg_test.cc b/src/reader/spirv/function_cfg_test.cc
index 9430456..5205d8b 100644
--- a/src/reader/spirv/function_cfg_test.cc
+++ b/src/reader/spirv/function_cfg_test.cc
@@ -2847,7 +2847,7 @@
EXPECT_EQ(constructs.size(), 2u);
EXPECT_THAT(ToString(constructs), Eq(R"(ConstructList{
Construct{ Function [0,4) begin_id:10 end_id:0 depth:0 parent:null }
- Construct{ Selection [0,3) begin_id:10 end_id:99 depth:1 parent:Function@10 }
+ Construct{ IfSelection [0,3) begin_id:10 end_id:99 depth:1 parent:Function@10 }
})")) << constructs;
// The block records the nearest enclosing construct.
EXPECT_EQ(fe.GetBlockInfo(10)->construct, constructs[1].get());
@@ -2894,7 +2894,7 @@
EXPECT_EQ(constructs.size(), 2u);
EXPECT_THAT(ToString(constructs), Eq(R"(ConstructList{
Construct{ Function [0,6) begin_id:5 end_id:0 depth:0 parent:null }
- Construct{ Selection [1,4) begin_id:10 end_id:99 depth:1 parent:Function@5 }
+ Construct{ IfSelection [1,4) begin_id:10 end_id:99 depth:1 parent:Function@5 }
})")) << constructs;
// The block records the nearest enclosing construct.
EXPECT_EQ(fe.GetBlockInfo(5)->construct, constructs[0].get());
@@ -2938,7 +2938,7 @@
EXPECT_EQ(constructs.size(), 2u);
EXPECT_THAT(ToString(constructs), Eq(R"(ConstructList{
Construct{ Function [0,5) begin_id:10 end_id:0 depth:0 parent:null }
- Construct{ Selection [0,4) begin_id:10 end_id:99 depth:1 parent:Function@10 }
+ Construct{ SwitchSelection [0,4) begin_id:10 end_id:99 depth:1 parent:Function@10 }
})")) << constructs;
// The block records the nearest enclosing construct.
EXPECT_EQ(fe.GetBlockInfo(10)->construct, constructs[1].get());
@@ -3070,7 +3070,7 @@
// it.
EXPECT_THAT(ToString(constructs), Eq(R"(ConstructList{
Construct{ Function [0,4) begin_id:10 end_id:0 depth:0 parent:null }
- Construct{ Selection [0,2) begin_id:10 end_id:50 depth:1 parent:Function@10 }
+ Construct{ IfSelection [0,2) begin_id:10 end_id:50 depth:1 parent:Function@10 }
Construct{ Continue [2,3) begin_id:50 end_id:99 depth:1 parent:Function@10 in-c:Continue@50 }
})")) << constructs;
// The block records the nearest enclosing construct.
@@ -3117,7 +3117,7 @@
EXPECT_EQ(constructs.size(), 4u);
EXPECT_THAT(ToString(constructs), Eq(R"(ConstructList{
Construct{ Function [0,5) begin_id:10 end_id:0 depth:0 parent:null }
- Construct{ Selection [0,2) begin_id:10 end_id:50 depth:1 parent:Function@10 }
+ Construct{ IfSelection [0,2) begin_id:10 end_id:50 depth:1 parent:Function@10 }
Construct{ Continue [3,4) begin_id:60 end_id:99 depth:1 parent:Function@10 in-c:Continue@60 }
Construct{ Loop [2,3) begin_id:50 end_id:60 depth:1 parent:Function@10 in-c-l:Loop@50 }
})")) << constructs;
@@ -3176,9 +3176,9 @@
EXPECT_EQ(constructs.size(), 4u);
EXPECT_THAT(ToString(constructs), Eq(R"(ConstructList{
Construct{ Function [0,9) begin_id:10 end_id:0 depth:0 parent:null }
- Construct{ Selection [0,8) begin_id:10 end_id:99 depth:1 parent:Function@10 }
- Construct{ Selection [1,3) begin_id:20 end_id:40 depth:2 parent:Selection@10 }
- Construct{ Selection [5,7) begin_id:50 end_id:89 depth:2 parent:Selection@10 }
+ Construct{ IfSelection [0,8) begin_id:10 end_id:99 depth:1 parent:Function@10 }
+ Construct{ IfSelection [1,3) begin_id:20 end_id:40 depth:2 parent:IfSelection@10 }
+ Construct{ IfSelection [5,7) begin_id:50 end_id:89 depth:2 parent:IfSelection@10 }
})")) << constructs;
// The block records the nearest enclosing construct.
EXPECT_EQ(fe.GetBlockInfo(10)->construct, constructs[1].get());
@@ -3237,9 +3237,9 @@
// The ordering among siblings depends on the computed block order.
EXPECT_THAT(ToString(constructs), Eq(R"(ConstructList{
Construct{ Function [0,8) begin_id:10 end_id:0 depth:0 parent:null }
- Construct{ Selection [0,7) begin_id:10 end_id:99 depth:1 parent:Function@10 }
- Construct{ Selection [1,3) begin_id:50 end_id:89 depth:2 parent:Selection@10 }
- Construct{ Selection [4,6) begin_id:20 end_id:49 depth:2 parent:Selection@10 }
+ Construct{ SwitchSelection [0,7) begin_id:10 end_id:99 depth:1 parent:Function@10 }
+ Construct{ IfSelection [1,3) begin_id:50 end_id:89 depth:2 parent:SwitchSelection@10 }
+ Construct{ IfSelection [4,6) begin_id:20 end_id:49 depth:2 parent:SwitchSelection@10 }
})")) << constructs;
// The block records the nearest enclosing construct.
EXPECT_EQ(fe.GetBlockInfo(10)->construct, constructs[1].get());
@@ -3286,8 +3286,8 @@
EXPECT_EQ(constructs.size(), 3u);
EXPECT_THAT(ToString(constructs), Eq(R"(ConstructList{
Construct{ Function [0,5) begin_id:10 end_id:0 depth:0 parent:null }
- Construct{ Selection [0,4) begin_id:10 end_id:99 depth:1 parent:Function@10 }
- Construct{ Selection [1,3) begin_id:20 end_id:89 depth:2 parent:Selection@10 }
+ Construct{ IfSelection [0,4) begin_id:10 end_id:99 depth:1 parent:Function@10 }
+ Construct{ SwitchSelection [1,3) begin_id:20 end_id:89 depth:2 parent:IfSelection@10 }
})")) << constructs;
// The block records the nearest enclosing construct.
EXPECT_EQ(fe.GetBlockInfo(10)->construct, constructs[1].get());
@@ -3397,7 +3397,7 @@
Construct{ Function [0,7) begin_id:10 end_id:0 depth:0 parent:null }
Construct{ Continue [5,6) begin_id:80 end_id:99 depth:1 parent:Function@10 in-c:Continue@80 }
Construct{ Loop [1,5) begin_id:20 end_id:80 depth:1 parent:Function@10 in-c-l:Loop@20 }
- Construct{ Selection [2,4) begin_id:30 end_id:49 depth:2 parent:Loop@20 in-c-l:Loop@20 }
+ Construct{ IfSelection [2,4) begin_id:30 end_id:49 depth:2 parent:Loop@20 in-c-l:Loop@20 }
})")) << constructs;
// The block records the nearest enclosing construct.
EXPECT_EQ(fe.GetBlockInfo(10)->construct, constructs[0].get());
@@ -3448,7 +3448,7 @@
Construct{ Function [0,6) begin_id:10 end_id:0 depth:0 parent:null }
Construct{ Continue [2,5) begin_id:30 end_id:99 depth:1 parent:Function@10 in-c:Continue@30 }
Construct{ Loop [1,2) begin_id:20 end_id:30 depth:1 parent:Function@10 in-c-l:Loop@20 }
- Construct{ Selection [2,4) begin_id:30 end_id:49 depth:2 parent:Continue@30 in-c:Continue@30 }
+ Construct{ IfSelection [2,4) begin_id:30 end_id:49 depth:2 parent:Continue@30 in-c:Continue@30 }
})")) << constructs;
// The block records the nearest enclosing construct.
EXPECT_EQ(fe.GetBlockInfo(10)->construct, constructs[0].get());
@@ -3490,8 +3490,8 @@
EXPECT_EQ(constructs.size(), 3u);
EXPECT_THAT(ToString(constructs), Eq(R"(ConstructList{
Construct{ Function [0,4) begin_id:10 end_id:0 depth:0 parent:null }
- Construct{ Selection [0,3) begin_id:10 end_id:99 depth:1 parent:Function@10 }
- Construct{ Continue [1,2) begin_id:20 end_id:89 depth:2 parent:Selection@10 in-c:Continue@20 }
+ Construct{ IfSelection [0,3) begin_id:10 end_id:99 depth:1 parent:Function@10 }
+ Construct{ Continue [1,2) begin_id:20 end_id:89 depth:2 parent:IfSelection@10 in-c:Continue@20 }
})")) << constructs;
// The block records the nearest enclosing construct.
EXPECT_EQ(fe.GetBlockInfo(10)->construct, constructs[1].get());
@@ -3539,9 +3539,9 @@
EXPECT_EQ(constructs.size(), 4u);
EXPECT_THAT(ToString(constructs), Eq(R"(ConstructList{
Construct{ Function [0,7) begin_id:10 end_id:0 depth:0 parent:null }
- Construct{ Selection [0,6) begin_id:10 end_id:99 depth:1 parent:Function@10 }
- Construct{ Continue [3,5) begin_id:40 end_id:89 depth:2 parent:Selection@10 in-c:Continue@40 }
- Construct{ Loop [1,3) begin_id:20 end_id:40 depth:2 parent:Selection@10 in-c-l:Loop@20 }
+ Construct{ IfSelection [0,6) begin_id:10 end_id:99 depth:1 parent:Function@10 }
+ Construct{ Continue [3,5) begin_id:40 end_id:89 depth:2 parent:IfSelection@10 in-c:Continue@40 }
+ Construct{ Loop [1,3) begin_id:20 end_id:40 depth:2 parent:IfSelection@10 in-c-l:Loop@20 }
})")) << constructs;
// The block records the nearest enclosing construct.
EXPECT_EQ(fe.GetBlockInfo(10)->construct, constructs[1].get());
