; RUN: llc < %s -march=x86-64 -mtriple=x86_64-unknown-linux-gnu -asm-verbose=false -post-RA-scheduler=true | FileCheck %s declare void @bar(i32) declare void @car(i32) declare void @dar(i32) declare void @ear(i32) declare void @far(i32) declare i1 @qux() @GHJK = global i32 0 @HABC = global i32 0 ; BranchFolding should tail-merge the stores since they all precede ; direct branches to the same place. ; CHECK-LABEL: tail_merge_me: ; CHECK-NOT: GHJK ; CHECK: movl $0, GHJK(%rip) ; CHECK-NEXT: movl $1, HABC(%rip) ; CHECK-NOT: GHJK define void @tail_merge_me() nounwind { entry: %a = call i1 @qux() br i1 %a, label %A, label %next next: %b = call i1 @qux() br i1 %b, label %B, label %C A: call void @bar(i32 0) store i32 0, i32* @GHJK br label %M B: call void @car(i32 1) store i32 0, i32* @GHJK br label %M C: call void @dar(i32 2) store i32 0, i32* @GHJK br label %M M: store i32 1, i32* @HABC %c = call i1 @qux() br i1 %c, label %return, label %altret return: call void @ear(i32 1000) ret void altret: call void @far(i32 1001) ret void } declare i8* @choose(i8*, i8*) ; BranchFolding should tail-duplicate the indirect jump to avoid ; redundant branching. ; CHECK-LABEL: tail_duplicate_me: ; CHECK: movl $0, GHJK(%rip) ; CHECK-NEXT: jmpq *%r ; CHECK: movl $0, GHJK(%rip) ; CHECK-NEXT: jmpq *%r ; CHECK: movl $0, GHJK(%rip) ; CHECK-NEXT: jmpq *%r define void @tail_duplicate_me() nounwind { entry: %a = call i1 @qux() %c = call i8* @choose(i8* blockaddress(@tail_duplicate_me, %return), i8* blockaddress(@tail_duplicate_me, %altret)) br i1 %a, label %A, label %next next: %b = call i1 @qux() br i1 %b, label %B, label %C A: call void @bar(i32 0) store i32 0, i32* @GHJK br label %M B: call void @car(i32 1) store i32 0, i32* @GHJK br label %M C: call void @dar(i32 2) store i32 0, i32* @GHJK br label %M M: indirectbr i8* %c, [label %return, label %altret] return: call void @ear(i32 1000) ret void altret: call void @far(i32 1001) ret void } ; BranchFolding shouldn't try to merge the tails of two blocks ; with only a branch in common, regardless of the fallthrough situation. ; CHECK-LABEL: dont_merge_oddly: ; CHECK-NOT: ret ; CHECK: ucomiss %xmm{{[0-2]}}, %xmm{{[0-2]}} ; CHECK-NEXT: jbe .LBB2_3 ; CHECK-NEXT: ucomiss %xmm{{[0-2]}}, %xmm{{[0-2]}} ; CHECK-NEXT: ja .LBB2_4 ; CHECK-NEXT: jmp .LBB2_2 ; CHECK-NEXT: .LBB2_3: ; CHECK-NEXT: ucomiss %xmm{{[0-2]}}, %xmm{{[0-2]}} ; CHECK-NEXT: jbe .LBB2_2 ; CHECK-NEXT: .LBB2_4: ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: ret ; CHECK-NEXT: .LBB2_2: ; CHECK-NEXT: movb $1, %al ; CHECK-NEXT: ret define i1 @dont_merge_oddly(float* %result) nounwind { entry: %tmp4 = getelementptr float* %result, i32 2 %tmp5 = load float* %tmp4, align 4 %tmp7 = getelementptr float* %result, i32 4 %tmp8 = load float* %tmp7, align 4 %tmp10 = getelementptr float* %result, i32 6 %tmp11 = load float* %tmp10, align 4 %tmp12 = fcmp olt float %tmp8, %tmp11 br i1 %tmp12, label %bb, label %bb21 bb: %tmp23469 = fcmp olt float %tmp5, %tmp8 br i1 %tmp23469, label %bb26, label %bb30 bb21: %tmp23 = fcmp olt float %tmp5, %tmp11 br i1 %tmp23, label %bb26, label %bb30 bb26: ret i1 0 bb30: ret i1 1 } ; Do any-size tail-merging when two candidate blocks will both require ; an unconditional jump to complete a two-way conditional branch. ; CHECK-LABEL: c_expand_expr_stmt: ; ; This test only works when register allocation happens to use %rax for both ; load addresses. ; ; CHE: jmp .LBB3_11 ; CHE-NEXT: .LBB3_9: ; CHE-NEXT: movq 8(%rax), %rax ; CHE-NEXT: xorl %edx, %edx ; CHE-NEXT: movb 16(%rax), %al ; CHE-NEXT: cmpb $16, %al ; CHE-NEXT: je .LBB3_11 ; CHE-NEXT: cmpb $23, %al ; CHE-NEXT: jne .LBB3_14 ; CHE-NEXT: .LBB3_11: %0 = type { %struct.rtx_def* } %struct.lang_decl = type opaque %struct.rtx_def = type { i16, i8, i8, [1 x %union.rtunion] } %struct.tree_decl = type { [24 x i8], i8*, i32, %union.tree_node*, i32, i8, i8, i8, i8, %union.tree_node*, %union.tree_node*, %union.tree_node*, %union.tree_node*, %union.tree_node*, %union.tree_node*, %union.tree_node*, %union.tree_node*, %union.tree_node*, %struct.rtx_def*, %union..2anon, %0, %union.tree_node*, %struct.lang_decl* } %union..2anon = type { i32 } %union.rtunion = type { i8* } %union.tree_node = type { %struct.tree_decl } define fastcc void @c_expand_expr_stmt(%union.tree_node* %expr) nounwind { entry: %tmp4 = load i8* null, align 8 ; [#uses=3] switch i8 %tmp4, label %bb3 [ i8 18, label %bb ] bb: ; preds = %entry switch i32 undef, label %bb1 [ i32 0, label %bb2.i i32 37, label %bb.i ] bb.i: ; preds = %bb switch i32 undef, label %bb1 [ i32 0, label %lvalue_p.exit ] bb2.i: ; preds = %bb br label %bb3 lvalue_p.exit: ; preds = %bb.i %tmp21 = load %union.tree_node** null, align 8 ; <%union.tree_node*> [#uses=3] %tmp22 = getelementptr inbounds %union.tree_node* %tmp21, i64 0, i32 0, i32 0, i64 0 ; [#uses=1] %tmp23 = load i8* %tmp22, align 8 ; [#uses=1] %tmp24 = zext i8 %tmp23 to i32 ; [#uses=1] switch i32 %tmp24, label %lvalue_p.exit4 [ i32 0, label %bb2.i3 i32 2, label %bb.i1 ] bb.i1: ; preds = %lvalue_p.exit %tmp25 = getelementptr inbounds %union.tree_node* %tmp21, i64 0, i32 0, i32 2 ; [#uses=1] %tmp26 = bitcast i32* %tmp25 to %union.tree_node** ; <%union.tree_node**> [#uses=1] %tmp27 = load %union.tree_node** %tmp26, align 8 ; <%union.tree_node*> [#uses=2] %tmp28 = getelementptr inbounds %union.tree_node* %tmp27, i64 0, i32 0, i32 0, i64 16 ; [#uses=1] %tmp29 = load i8* %tmp28, align 8 ; [#uses=1] %tmp30 = zext i8 %tmp29 to i32 ; [#uses=1] switch i32 %tmp30, label %lvalue_p.exit4 [ i32 0, label %bb2.i.i2 i32 2, label %bb.i.i ] bb.i.i: ; preds = %bb.i1 %tmp34 = tail call fastcc i32 @lvalue_p(%union.tree_node* null) nounwind ; [#uses=1] %phitmp = icmp ne i32 %tmp34, 0 ; [#uses=1] br label %lvalue_p.exit4 bb2.i.i2: ; preds = %bb.i1 %tmp35 = getelementptr inbounds %union.tree_node* %tmp27, i64 0, i32 0, i32 0, i64 8 ; [#uses=1] %tmp36 = bitcast i8* %tmp35 to %union.tree_node** ; <%union.tree_node**> [#uses=1] %tmp37 = load %union.tree_node** %tmp36, align 8 ; <%union.tree_node*> [#uses=1] %tmp38 = getelementptr inbounds %union.tree_node* %tmp37, i64 0, i32 0, i32 0, i64 16 ; [#uses=1] %tmp39 = load i8* %tmp38, align 8 ; [#uses=1] switch i8 %tmp39, label %bb2 [ i8 16, label %lvalue_p.exit4 i8 23, label %lvalue_p.exit4 ] bb2.i3: ; preds = %lvalue_p.exit %tmp40 = getelementptr inbounds %union.tree_node* %tmp21, i64 0, i32 0, i32 0, i64 8 ; [#uses=1] %tmp41 = bitcast i8* %tmp40 to %union.tree_node** ; <%union.tree_node**> [#uses=1] %tmp42 = load %union.tree_node** %tmp41, align 8 ; <%union.tree_node*> [#uses=1] %tmp43 = getelementptr inbounds %union.tree_node* %tmp42, i64 0, i32 0, i32 0, i64 16 ; [#uses=1] %tmp44 = load i8* %tmp43, align 8 ; [#uses=1] switch i8 %tmp44, label %bb2 [ i8 16, label %lvalue_p.exit4 i8 23, label %lvalue_p.exit4 ] lvalue_p.exit4: ; preds = %bb2.i3, %bb2.i3, %bb2.i.i2, %bb2.i.i2, %bb.i.i, %bb.i1, %lvalue_p.exit %tmp45 = phi i1 [ %phitmp, %bb.i.i ], [ false, %bb2.i.i2 ], [ false, %bb2.i.i2 ], [ false, %bb.i1 ], [ false, %bb2.i3 ], [ false, %bb2.i3 ], [ false, %lvalue_p.exit ] ; [#uses=1] %tmp46 = icmp eq i8 %tmp4, 0 ; [#uses=1] %or.cond = or i1 %tmp45, %tmp46 ; [#uses=1] br i1 %or.cond, label %bb2, label %bb3 bb1: ; preds = %bb2.i.i, %bb.i, %bb %.old = icmp eq i8 %tmp4, 23 ; [#uses=1] br i1 %.old, label %bb2, label %bb3 bb2: ; preds = %bb1, %lvalue_p.exit4, %bb2.i3, %bb2.i.i2 br label %bb3 bb3: ; preds = %bb2, %bb1, %lvalue_p.exit4, %bb2.i, %entry %expr_addr.0 = phi %union.tree_node* [ null, %bb2 ], [ %expr, %bb2.i ], [ %expr, %entry ], [ %expr, %bb1 ], [ %expr, %lvalue_p.exit4 ] ; <%union.tree_node*> [#uses=0] unreachable } declare fastcc i32 @lvalue_p(%union.tree_node* nocapture) nounwind readonly declare fastcc %union.tree_node* @default_conversion(%union.tree_node*) nounwind ; If one tail merging candidate falls through into the other, ; tail merging is likely profitable regardless of how few ; instructions are involved. This function should have only ; one ret instruction. ; CHECK-LABEL: foo: ; CHECK: callq func ; CHECK-NEXT: .LBB4_2: ; CHECK-NEXT: popq ; CHECK-NEXT: ret define void @foo(i1* %V) nounwind { entry: %t0 = icmp eq i1* %V, null br i1 %t0, label %return, label %bb bb: call void @func() ret void return: ret void } declare void @func() ; one - One instruction may be tail-duplicated even with optsize. ; CHECK-LABEL: one: ; CHECK: movl $0, XYZ(%rip) ; CHECK: movl $0, XYZ(%rip) @XYZ = external global i32 define void @one() nounwind optsize { entry: %0 = icmp eq i32 undef, 0 br i1 %0, label %bbx, label %bby bby: switch i32 undef, label %bb7 [ i32 16, label %return ] bb7: store volatile i32 0, i32* @XYZ unreachable bbx: switch i32 undef, label %bb12 [ i32 128, label %return ] bb12: store volatile i32 0, i32* @XYZ unreachable return: ret void } ; two - Same as one, but with two instructions in the common ; tail instead of one. This is too much to be merged, given ; the optsize attribute. ; CHECK-LABEL: two: ; CHECK-NOT: XYZ ; CHECK: ret ; CHECK: movl $0, XYZ(%rip) ; CHECK: movl $1, XYZ(%rip) ; CHECK-NOT: XYZ define void @two() nounwind optsize { entry: %0 = icmp eq i32 undef, 0 br i1 %0, label %bbx, label %bby bby: switch i32 undef, label %bb7 [ i32 16, label %return ] bb7: store volatile i32 0, i32* @XYZ store volatile i32 1, i32* @XYZ unreachable bbx: switch i32 undef, label %bb12 [ i32 128, label %return ] bb12: store volatile i32 0, i32* @XYZ store volatile i32 1, i32* @XYZ unreachable return: ret void } ; two_nosize - Same as two, but without the optsize attribute. ; Now two instructions are enough to be tail-duplicated. ; CHECK-LABEL: two_nosize: ; CHECK: movl $0, XYZ(%rip) ; CHECK: movl $1, XYZ(%rip) ; CHECK: movl $0, XYZ(%rip) ; CHECK: movl $1, XYZ(%rip) define void @two_nosize() nounwind { entry: %0 = icmp eq i32 undef, 0 br i1 %0, label %bbx, label %bby bby: switch i32 undef, label %bb7 [ i32 16, label %return ] bb7: store volatile i32 0, i32* @XYZ store volatile i32 1, i32* @XYZ unreachable bbx: switch i32 undef, label %bb12 [ i32 128, label %return ] bb12: store volatile i32 0, i32* @XYZ store volatile i32 1, i32* @XYZ unreachable return: ret void } ; Tail-merging should merge the two ret instructions since one side ; can fall-through into the ret and the other side has to branch anyway. ; CHECK-LABEL: TESTE: ; CHECK: ret ; CHECK-NOT: ret ; CHECK: size TESTE define i64 @TESTE(i64 %parami, i64 %paraml) nounwind readnone { entry: %cmp = icmp slt i64 %parami, 1 ; [#uses=1] %varx.0 = select i1 %cmp, i64 1, i64 %parami ; [#uses=1] %cmp410 = icmp slt i64 %paraml, 1 ; [#uses=1] br i1 %cmp410, label %for.end, label %bb.nph bb.nph: ; preds = %entry %tmp15 = mul i64 %paraml, %parami ; [#uses=1] ret i64 %tmp15 for.end: ; preds = %entry ret i64 %varx.0 }