[GlobalISel] Insert translated switch icmp blocks after switch parent.

Now that we preserve the IR layout, we would end up with all the newly
synthesized switch comparison blocks at the end of the function.
Instead, use a hopefully more reasonable layout, with the comparison
blocks immediately following the switch comparison blocks.

llvm-svn: 297869

2 files changed, 23 insertions, 16 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 2bcb5559101..353c4a22fe6 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -258,7 +258,8 @@ bool IRTranslator::translateSwitch(const User &U,
 
     MachineBasicBlock *FalseMBB =
         MF->CreateMachineBasicBlock(SwInst.getParent());
-    MF->push_back(FalseMBB);
+    // Insert the comparison blocks one after the other.
+    MF->insert(std::next(CurMBB.getIterator()), FalseMBB);
     MIRBuilder.buildBr(*FalseMBB);
     CurMBB.addSuccessor(FalseMBB);
 
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
index d4de7280320..88cb2554691 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
@@ -117,7 +117,17 @@ false:
 ; CHECK: G_BRCOND %[[regicmp100]](s1), %[[BB_CASE100]]
 ; CHECK: G_BR %[[BB_NOTCASE100_CHECKNEXT]]
 ;
-; CHECK: [[BB_DEFAULT:bb.[0-9]+.default]]:
+; CHECK: [[BB_NOTCASE100_CHECKNEXT]]:
+; CHECK-NEXT: successors: %[[BB_CASE200:bb.[0-9]+.case200]](0x40000000), %[[BB_NOTCASE200_CHECKNEXT:bb.[0-9]+.entry]](0x40000000)
+; CHECK: %[[regicmp200:[0-9]+]](s1) = G_ICMP intpred(eq), %[[reg200]](s32), %0
+; CHECK: G_BRCOND %[[regicmp200]](s1), %[[BB_CASE200]]
+; CHECK: G_BR %[[BB_NOTCASE200_CHECKNEXT]]
+;
+; CHECK: [[BB_NOTCASE200_CHECKNEXT]]:
+; CHECK-NEXT: successors: %[[BB_DEFAULT:bb.[0-9]+.default]](0x80000000)
+; CHECK: G_BR %[[BB_DEFAULT]]
+;
+; CHECK: [[BB_DEFAULT]]:
 ; CHECK-NEXT: successors: %[[BB_RET:bb.[0-9]+.return]](0x80000000)
 ; CHECK: %[[regretdefault:[0-9]+]](s32) = G_ADD %0, %[[reg0]]
 ; CHECK: G_BR %[[BB_RET]]
@@ -127,7 +137,7 @@ false:
 ; CHECK: %[[regretc100:[0-9]+]](s32) = G_ADD %0, %[[reg1]]
 ; CHECK: G_BR %[[BB_RET]]
 ;
-; CHECK: [[BB_CASE200:bb.[0-9]+.case200]]:
+; CHECK: [[BB_CASE200]]:
 ; CHECK-NEXT: successors: %[[BB_RET]](0x80000000)
 ; CHECK: %[[regretc200:[0-9]+]](s32) = G_ADD %0, %[[reg2]]
 ; CHECK: G_BR %[[BB_RET]]
@@ -137,15 +147,6 @@ false:
 ; CHECK:  %w0 = COPY %[[regret]](s32)
 ; CHECK:  RET_ReallyLR implicit %w0
 ;
-; CHECK: [[BB_NOTCASE100_CHECKNEXT]]:
-; CHECK-NEXT: successors: %[[BB_CASE200]](0x40000000), %[[BB_NOTCASE200_CHECKNEXT:bb.[0-9]+.entry]](0x40000000)
-; CHECK: %[[regicmp200:[0-9]+]](s1) = G_ICMP intpred(eq), %[[reg200]](s32), %0
-; CHECK: G_BRCOND %[[regicmp200]](s1), %[[BB_CASE200]]
-; CHECK: G_BR %[[BB_NOTCASE200_CHECKNEXT]]
-;
-; CHECK: [[BB_NOTCASE200_CHECKNEXT]]:
-; CHECK-NEXT: successors: %[[BB_DEFAULT]](0x80000000)
-; CHECK: G_BR %[[BB_DEFAULT]]
 define i32 @switch(i32 %argc) {
 entry:
   switch i32 %argc, label %default [
@@ -174,12 +175,17 @@ return:
   ; %entry block is no longer a predecessor for the phi instruction. We need to
   ; use the correct lowered MachineBasicBlock instead.
 ; CHECK-LABEL: name: test_cfg_remap
-; CHECK: [[PHI_BLOCK:bb.[0-9]+.phi.block]]:
-; CHECK-NEXT: PHI %{{.*}}(s32), %[[NOTCASE57_BLOCK:bb.[0-9]+.entry]], %{{.*}}(s32),
-
+; CHECK: {{bb.[0-9]+.entry}}:
+; CHECK-NEXT: successors: %{{bb.[0-9]+.next}}(0x40000000), %[[NOTCASE1_BLOCK:bb.[0-9]+.entry]](0x40000000)
+; CHECK: [[NOTCASE1_BLOCK]]:
+; CHECK-NEXT: successors: %{{bb.[0-9]+.other}}(0x40000000), %[[NOTCASE57_BLOCK:bb.[0-9]+.entry]](0x40000000)
 ; CHECK: [[NOTCASE57_BLOCK]]:
-; CHECK-NEXT: successors: %[[PHI_BLOCK]]
+; CHECK-NEXT: successors: %[[PHI_BLOCK:bb.[0-9]+.phi.block]](0x80000000)
 ; CHECK: G_BR %[[PHI_BLOCK]]
+;
+; CHECK: [[PHI_BLOCK]]:
+; CHECK-NEXT: PHI %{{.*}}(s32), %[[NOTCASE57_BLOCK:bb.[0-9]+.entry]], %{{.*}}(s32),
+;
 define i32 @test_cfg_remap(i32 %in) {
 entry:
   switch i32 %in, label %phi.block [i32 1, label %next