[llvm] r288720 - GlobalISel: place constants correctly in the entry block.

[Tim Northover via llvm-commits]

Author: tnorthover
Date: Mon Dec  5 16:40:13 2016
New Revision: 288720

URL: http://llvm.org/viewvc/llvm-project?rev=288720&view=rev
Log:
GlobalISel: place constants correctly in the entry block.

When the entry block was empty after arg lowering, we were always placing
constants at the end. This is probably hamrless while translating the same
block, but horribly wrong once its terminator has been translated. So switch to
inserting at the beginning.

Modified:
    llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp
    llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
    llvm/trunk/test/CodeGen/AArch64/GlobalISel/call-translator-ios.ll
    llvm/trunk/test/CodeGen/AArch64/GlobalISel/call-translator.ll

Modified: llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp?rev=288720&r1=288719&r2=288720&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp (original)
+++ llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp Mon Dec  5 16:40:13 2016
@@ -766,7 +766,7 @@ bool IRTranslator::runOnMachineFunction(
   // Now that we've got the ABI handling code, it's safe to set a location for
   // any Constants we find in the IR.
   if (MBB.empty())
-    EntryBuilder.setMBB(MBB);
+    EntryBuilder.setMBB(MBB, /* Beginning */ true);
   else
     EntryBuilder.setInstr(MBB.back(), /* Before */ false);
 

Modified: llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll?rev=288720&r1=288719&r2=288720&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll Mon Dec  5 16:40:13 2016
@@ -1,4 +1,4 @@
-; RUN: llc -O0 -stop-after=irtranslator -global-isel -verify-machineinstrs %s -o - 2>&1 | FileCheck %s
+; RUN: llc -O0 -aarch64-enable-atomic-cfg-tidy=0 -stop-after=irtranslator -global-isel -verify-machineinstrs %s -o - 2>&1 | FileCheck %s
 
 ; This file checks that the translation from llvm IR to generic MachineInstr
 ; is correct.
@@ -383,8 +383,8 @@ next:
 }
 
 ; CHECK-LABEL: name: constant_int_start
-; CHECK: [[TWO:%[0-9]+]](s32) = G_CONSTANT i32 2
 ; CHECK: [[ANSWER:%[0-9]+]](s32) = G_CONSTANT i32 42
+; CHECK: [[TWO:%[0-9]+]](s32) = G_CONSTANT i32 2
 ; CHECK: [[RES:%[0-9]+]](s32) = G_ADD [[TWO]], [[ANSWER]]
 define i32 @constant_int_start() {
   %res = add i32 2, 42
@@ -915,3 +915,17 @@ define void @test_large_const(i128* %add
   store i128 42, i128* %addr
   ret void
 }
+
+; When there was no formal argument handling (so the first BB was empty) we used
+; to insert the constants at the end of the block, even if they were encountered
+; after the block's terminators had been emitted.
+define i32 @test_const_placement() {
+; CHECK-LABEL: name: test_const_placement
+; CHECK: [[VAL:%[0-9]+]](s32) = G_CONSTANT i32 42
+; CHECK: G_BR
+
+  br label %next
+
+next:
+  ret i32 42
+}

Modified: llvm/trunk/test/CodeGen/AArch64/GlobalISel/call-translator-ios.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/GlobalISel/call-translator-ios.ll?rev=288720&r1=288719&r2=288720&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/GlobalISel/call-translator-ios.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/GlobalISel/call-translator-ios.ll Mon Dec  5 16:40:13 2016
@@ -18,8 +18,8 @@ define signext i8 @test_stack_slots([8 x
 }
 
 ; CHECK-LABEL: name: test_call_stack
-; CHECK: [[C42:%[0-9]+]](s8) = G_CONSTANT i8 42
 ; CHECK: [[C12:%[0-9]+]](s8) = G_CONSTANT i8 12
+; CHECK: [[C42:%[0-9]+]](s8) = G_CONSTANT i8 42
 ; CHECK: [[SP:%[0-9]+]](p0) = COPY %sp
 ; CHECK: [[C42_OFFS:%[0-9]+]](s64) = G_CONSTANT i64 0
 ; CHECK: [[C42_LOC:%[0-9]+]](p0) = G_GEP [[SP]], [[C42_OFFS]](s64)

Modified: llvm/trunk/test/CodeGen/AArch64/GlobalISel/call-translator.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/GlobalISel/call-translator.ll?rev=288720&r1=288719&r2=288720&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/GlobalISel/call-translator.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/GlobalISel/call-translator.ll Mon Dec  5 16:40:13 2016
@@ -162,9 +162,9 @@ define void @test_stack_slots([8 x i64],
 }
 
 ; CHECK-LABEL: name: test_call_stack
-; CHECK: [[C42:%[0-9]+]](s64) = G_CONSTANT i64 42
-; CHECK: [[C12:%[0-9]+]](s64) = G_CONSTANT i64 12
 ; CHECK: [[PTR:%[0-9]+]](p0) = G_CONSTANT i64 0
+; CHECK: [[C12:%[0-9]+]](s64) = G_CONSTANT i64 12
+; CHECK: [[C42:%[0-9]+]](s64) = G_CONSTANT i64 42
 ; CHECK: [[SP:%[0-9]+]](p0) = COPY %sp
 ; CHECK: [[C42_OFFS:%[0-9]+]](s64) = G_CONSTANT i64 0
 ; CHECK: [[C42_LOC:%[0-9]+]](p0) = G_GEP [[SP]], [[C42_OFFS]](s64)