Tidy up LLVM labels for branches

3 files changed, 37 insertions, 22 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGen.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGen.java
index 36898220..a0d04143 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGen.java
@@ -156,13 +156,13 @@ public class LlvmCodeGen {
                 context = condition1Result.context();
 
                 var ifTrueLabelResult = context.generateVariableLocal(
-                    LlvmCodeGenLocalVariableSpace.IF_TRUE
+                    LlvmCodeGenLocalVariableSpace.IF_TRUE_START
                 );
                 var ifTrueLabel = ifTrueLabelResult.value();
                 context = ifTrueLabelResult.context();
 
                 var ifFalseLabelResult = context.generateVariableLocal(
-                    LlvmCodeGenLocalVariableSpace.IF_FALSE
+                    LlvmCodeGenLocalVariableSpace.IF_FALSE_START
                 );
                 var ifFalseLabel = ifFalseLabelResult.value();
                 context = ifFalseLabelResult.context();
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenLocalVariableSpace.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenLocalVariableSpace.java
index a8149228..ba5019c2 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenLocalVariableSpace.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenLocalVariableSpace.java
@@ -12,8 +12,10 @@ public enum LlvmCodeGenLocalVariableSpace {
     FIELD("field"),
     FIELD_POINTER("fieldPointer"),
     IF_END("ifEnd"),
-    IF_FALSE("ifFalse"),
-    IF_TRUE("ifTrue"),
+    IF_FALSE_START("ifFalseStart"),
+    IF_FALSE_END("ifFalseEnd"),
+    IF_TRUE_START("ifTrueStart"),
+    IF_TRUE_END("ifTrueEnd"),
     LOCAL("local"),
     NAMESPACE("namespace"),
     NAMESPACE_STRUCT_POINTER("namespaceStructPointer"),
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java
index ef8f8355..a9919af8 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java
@@ -262,17 +262,29 @@ public class LlvmPatioCodeGen {
             }
 
             case PatioIf patioIf -> {
-                var ifTrueLabelResult = context.allocateLocalName(
-                    LlvmCodeGenLocalVariableSpace.IF_TRUE
+                var ifTrueStartLabelResult = context.allocateLocalName(
+                    LlvmCodeGenLocalVariableSpace.IF_TRUE_START
                 );
-                var ifTrueLabel = ifTrueLabelResult.value();
-                context = ifTrueLabelResult.context();
+                var ifTrueStartLabel = ifTrueStartLabelResult.value();
+                context = ifTrueStartLabelResult.context();
 
-                var ifFalseLabelResult = context.allocateLocalName(
-                    LlvmCodeGenLocalVariableSpace.IF_FALSE
+                var ifTrueEndLabelResult = context.allocateLocalName(
+                    LlvmCodeGenLocalVariableSpace.IF_TRUE_END
                 );
-                var ifFalseLabel = ifFalseLabelResult.value();
-                context = ifFalseLabelResult.context();
+                var ifTrueEndLabel = ifTrueEndLabelResult.value();
+                context = ifTrueEndLabelResult.context();
+
+                var ifFalseStartLabelResult = context.allocateLocalName(
+                    LlvmCodeGenLocalVariableSpace.IF_FALSE_START
+                );
+                var ifFalseStartLabel = ifFalseStartLabelResult.value();
+                context = ifFalseStartLabelResult.context();
+
+                var ifFalseEndLabelResult = context.allocateLocalName(
+                    LlvmCodeGenLocalVariableSpace.IF_FALSE_END
+                );
+                var ifFalseEndLabel = ifFalseEndLabelResult.value();
+                context = ifFalseEndLabelResult.context();
 
                 var endLabelResult = context.allocateLocalName(
                     LlvmCodeGenLocalVariableSpace.IF_END
@@ -282,20 +294,21 @@ public class LlvmPatioCodeGen {
 
                 context = context.addTerminatorInstruction(new LlvmBr(
                     patioOperandToLlvmOperand(patioIf.condition(), context),
-                    ifTrueLabel.name(),
-                    ifFalseLabel.name()
+                    ifTrueStartLabel.name(),
+                    ifFalseStartLabel.name()
                 ));
 
-                context = context.setBasicBlockLabel(ifTrueLabel.name());
+                context = context.setBasicBlockLabel(ifTrueStartLabel.name());
                 context = generateInstructions(patioIf.trueBody().body(), context);
-                // TODO: remove this hack!
-                var ifTrueEndLabel = context.basicBlockLabel.orElseThrow();
+                // TODO: only allow basic block label to be set with terminator instruction?
+                context = context.addTerminatorInstruction(new LlvmBrUnconditional(ifTrueEndLabel.name()));
+                context = context.setBasicBlockLabel(ifTrueEndLabel.name());
                 context = context.addTerminatorInstruction(new LlvmBrUnconditional(endLabel.name()));
 
-                context = context.setBasicBlockLabel(ifFalseLabel.name());
+                context = context.setBasicBlockLabel(ifFalseStartLabel.name());
                 context = generateInstructions(patioIf.falseBody().body(), context);
-                // TODO: remove this hack!
-                var ifFalseEndLabel = context.basicBlockLabel.orElseThrow();
+                context = context.addTerminatorInstruction(new LlvmBrUnconditional(ifFalseEndLabel.name()));
+                context = context.setBasicBlockLabel(ifFalseEndLabel.name());
                 context = context.addTerminatorInstruction(new LlvmBrUnconditional(endLabel.name()));
 
                 context = context.setBasicBlockLabel(endLabel.name());
@@ -313,11 +326,11 @@ public class LlvmPatioCodeGen {
                         List.of(
                             new LlvmPhiPair(
                                 patioOperandToLlvmOperand(patioIf.trueBody().results().get(targetIndex), context),
-                                new LlvmVariableLocal(ifTrueEndLabel)
+                                ifTrueEndLabel
                             ),
                             new LlvmPhiPair(
                                 patioOperandToLlvmOperand(patioIf.falseBody().results().get(targetIndex), context),
-                                new LlvmVariableLocal(ifFalseEndLabel)
+                                ifFalseEndLabel
                             )
                         )
                     ));