- Stop simplifycfg from duplicating "ret" instructions into unconditional

  branches. PR8575, rdar://5134905, rdar://8911460.
- Allow codegen tail duplication to dup small return blocks after register
  allocation is done.

llvm-svn: 124462

2 files changed, 6 insertions, 55 deletions

diff --git a/llvm/test/CodeGen/X86/critical-edge-split.ll b/llvm/test/CodeGen/X86/critical-edge-split.ll
deleted file mode 100644
index 96fef0fbfc6..00000000000
--- a/llvm/test/CodeGen/X86/critical-edge-split.ll
+++ /dev/null
@@ -1,50 +0,0 @@
-; RUN: llc < %s -mtriple=i386-apple-darwin -o /dev/null -stats -info-output-file - | grep asm-printer | grep 29
-
-	%CC = type { %Register }
-	%II = type { %"struct.XX::II::$_74" }
-	%JITFunction = type %YYValue* (%CC*, %YYValue**)
-	%YYValue = type { i32 (...)** }
-	%Register = type { %"struct.XX::ByteCodeFeatures" }
-	%"struct.XX::ByteCodeFeatures" = type { i32 }
-	%"struct.XX::II::$_74" = type { i8* }
-@llvm.used = appending global [1 x i8*] [ i8* bitcast (%JITFunction* @loop to i8*) ], section "llvm.metadata"		; <[1 x i8*]*> [#uses=0]
-
-define %YYValue* @loop(%CC*, %YYValue**) nounwind {
-; <label>:2
-	%3 = getelementptr %CC* %0, i32 -9		; <%CC*> [#uses=1]
-	%4 = bitcast %CC* %3 to %YYValue**		; <%YYValue**> [#uses=2]
-	%5 = load %YYValue** %4		; <%YYValue*> [#uses=3]
-	%unique_1.i = ptrtoint %YYValue* %5 to i1		; <i1> [#uses=1]
-	br i1 %unique_1.i, label %loop, label %11
-
-loop:		; preds = %6, %2
-	%.1 = phi %YYValue* [ inttoptr (i32 1 to %YYValue*), %2 ], [ %intAddValue, %6 ]		; <%YYValue*> [#uses=3]
-	%immediateCmp = icmp slt %YYValue* %.1, %5		; <i1> [#uses=1]
-	br i1 %immediateCmp, label %6, label %8
-
-; <label>:6		; preds = %loop
-	%lhsInt = ptrtoint %YYValue* %.1 to i32		; <i32> [#uses=1]
-	%7 = call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %lhsInt, i32 2)		; <{ i32, i1 }> [#uses=2]
-	%intAdd = extractvalue { i32, i1 } %7, 0		; <i32> [#uses=1]
-	%intAddValue = inttoptr i32 %intAdd to %YYValue*		; <%YYValue*> [#uses=1]
-	%intAddOverflow = extractvalue { i32, i1 } %7, 1		; <i1> [#uses=1]
-	br i1 %intAddOverflow, label %.loopexit, label %loop
-
-; <label>:8		; preds = %loop
-	ret %YYValue* inttoptr (i32 10 to %YYValue*)
-
-.loopexit:		; preds = %6
-	%9 = bitcast %CC* %0 to %YYValue**		; <%YYValue**> [#uses=1]
-	store %YYValue* %.1, %YYValue** %9
-	store %YYValue* %5, %YYValue** %4
-	%10 = call fastcc %YYValue* @foobar(%II* inttoptr (i32 3431104 to %II*), %CC* %0, %YYValue** %1)		; <%YYValue*> [#uses=1]
-	ret %YYValue* %10
-
-; <label>:11		; preds = %2
-	%12 = call fastcc %YYValue* @foobar(%II* inttoptr (i32 3431080 to %II*), %CC* %0, %YYValue** %1)		; <%YYValue*> [#uses=1]
-	ret %YYValue* %12
-}
-
-declare fastcc %YYValue* @foobar(%II*, %CC*, %YYValue**) nounwind
-
-declare { i32, i1 } @llvm.sadd.with.overflow.i32(i32, i32) nounwind
diff --git a/llvm/test/CodeGen/X86/loop-blocks.ll b/llvm/test/CodeGen/X86/loop-blocks.ll
index 354d0820697..faba6300712 100644
--- a/llvm/test/CodeGen/X86/loop-blocks.ll
+++ b/llvm/test/CodeGen/X86/loop-blocks.ll
@@ -70,6 +70,7 @@ exit:
 
 ; Same as slightly_more_involved, but block_a is now a CFG diamond with
 ; fallthrough edges which should be preserved.
+; "callq block_a_merge_func" is tail duped.
 
 ; CHECK: yet_more_involved:
 ;      CHECK:   jmp .LBB2_1
@@ -78,12 +79,12 @@ exit:
 ; CHECK-NEXT:   callq bar99
 ; CHECK-NEXT:   callq get
 ; CHECK-NEXT:   cmpl $2999, %eax
-; CHECK-NEXT:   jg .LBB2_6
-; CHECK-NEXT:   callq block_a_true_func
-; CHECK-NEXT:   jmp .LBB2_7
-; CHECK-NEXT: .LBB2_6:
+; CHECK-NEXT:   jle .LBB2_5
 ; CHECK-NEXT:   callq block_a_false_func
-; CHECK-NEXT: .LBB2_7:
+; CHECK-NEXT:   callq block_a_merge_func
+; CHECK-NEXT:   jmp .LBB2_1
+; CHECK-NEXT: .LBB2_5:
+; CHECK-NEXT:   callq block_a_true_func
 ; CHECK-NEXT:   callq block_a_merge_func
 ; CHECK-NEXT: .LBB2_1:
 ; CHECK-NEXT:   callq body