; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -post-RA-scheduler=true | FileCheck %s declare dso_local void @bar(i32) declare dso_local void @car(i32) declare dso_local void @dar(i32) declare dso_local void @ear(i32) declare dso_local void @far(i32) declare i1 @qux() @GHJK = dso_local global i32 0 @HABC = dso_local global i32 0 ; BranchFolding should tail-merge the stores since they all precede ; direct branches to the same place. define dso_local void @tail_merge_me() nounwind { ; CHECK-LABEL: tail_merge_me: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: pushq %rax ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB0_1 ; CHECK-NEXT: # %bb.6: # %A ; CHECK-NEXT: xorl %edi, %edi ; CHECK-NEXT: callq bar ; CHECK-NEXT: jmp .LBB0_4 ; CHECK-NEXT: .LBB0_1: # %next ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB0_3 ; CHECK-NEXT: # %bb.2: # %B ; CHECK-NEXT: movl $1, %edi ; CHECK-NEXT: callq car ; CHECK-NEXT: jmp .LBB0_4 ; CHECK-NEXT: .LBB0_3: # %C ; CHECK-NEXT: movl $2, %edi ; CHECK-NEXT: callq dar ; CHECK-NEXT: .LBB0_4: # %M ; CHECK-NEXT: movl $0, {{.*}}(%rip) ; CHECK-NEXT: movl $1, {{.*}}(%rip) ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB0_5 ; CHECK-NEXT: # %bb.7: # %return ; CHECK-NEXT: movl $1000, %edi # imm = 0x3E8 ; CHECK-NEXT: callq ear ; CHECK-NEXT: popq %rax ; CHECK-NEXT: retq ; CHECK-NEXT: .LBB0_5: # %altret ; CHECK-NEXT: movl $1001, %edi # imm = 0x3E9 ; CHECK-NEXT: callq far ; CHECK-NEXT: popq %rax ; CHECK-NEXT: retq 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. define dso_local void @tail_duplicate_me() nounwind { ; CHECK-LABEL: tail_duplicate_me: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: pushq %r14 ; CHECK-NEXT: pushq %rbx ; CHECK-NEXT: pushq %rax ; CHECK-NEXT: callq qux ; CHECK-NEXT: movl $.Ltmp0, %edi ; CHECK-NEXT: movl $.Ltmp1, %esi ; CHECK-NEXT: movl %eax, %ebx ; CHECK-NEXT: callq choose ; CHECK-NEXT: movq %rax, %r14 ; CHECK-NEXT: testb $1, %bl ; CHECK-NEXT: je .LBB1_1 ; CHECK-NEXT: # %bb.7: # %A ; CHECK-NEXT: xorl %edi, %edi ; CHECK-NEXT: callq bar ; CHECK-NEXT: movl $0, {{.*}}(%rip) ; CHECK-NEXT: jmpq *%r14 ; CHECK-NEXT: .Ltmp0: # Block address taken ; CHECK-NEXT: .LBB1_4: # %return ; CHECK-NEXT: movl $1000, %edi # imm = 0x3E8 ; CHECK-NEXT: callq ear ; CHECK-NEXT: jmp .LBB1_5 ; CHECK-NEXT: .LBB1_1: # %next ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB1_3 ; CHECK-NEXT: # %bb.2: # %B ; CHECK-NEXT: movl $1, %edi ; CHECK-NEXT: callq car ; CHECK-NEXT: movl $0, {{.*}}(%rip) ; CHECK-NEXT: jmpq *%r14 ; CHECK-NEXT: .Ltmp1: # Block address taken ; CHECK-NEXT: .LBB1_6: # %altret ; CHECK-NEXT: movl $1001, %edi # imm = 0x3E9 ; CHECK-NEXT: callq far ; CHECK-NEXT: .LBB1_5: # %return ; CHECK-NEXT: addq $8, %rsp ; CHECK-NEXT: popq %rbx ; CHECK-NEXT: popq %r14 ; CHECK-NEXT: retq ; CHECK-NEXT: .LBB1_3: # %C ; CHECK-NEXT: movl $2, %edi ; CHECK-NEXT: callq dar ; CHECK-NEXT: movl $0, {{.*}}(%rip) ; CHECK-NEXT: jmpq *%r14 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. define i1 @dont_merge_oddly(float* %result) nounwind { ; CHECK-LABEL: dont_merge_oddly: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: movss {{.*#+}} xmm1 = mem[0],zero,zero,zero ; CHECK-NEXT: movss {{.*#+}} xmm2 = mem[0],zero,zero,zero ; CHECK-NEXT: movss {{.*#+}} xmm0 = mem[0],zero,zero,zero ; CHECK-NEXT: ucomiss %xmm1, %xmm2 ; CHECK-NEXT: jbe .LBB2_3 ; CHECK-NEXT: # %bb.1: # %bb ; CHECK-NEXT: ucomiss %xmm0, %xmm1 ; CHECK-NEXT: ja .LBB2_4 ; CHECK-NEXT: .LBB2_2: # %bb30 ; CHECK-NEXT: movb $1, %al ; CHECK-NEXT: retq ; CHECK-NEXT: .LBB2_3: # %bb21 ; CHECK-NEXT: ucomiss %xmm0, %xmm2 ; CHECK-NEXT: jbe .LBB2_2 ; CHECK-NEXT: .LBB2_4: # %bb26 ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: retq entry: %tmp4 = getelementptr float, float* %result, i32 2 %tmp5 = load float, float* %tmp4, align 4 %tmp7 = getelementptr float, float* %result, i32 4 %tmp8 = load float, float* %tmp7, align 4 %tmp10 = getelementptr float, float* %result, i32 6 %tmp11 = load float, 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. ; ; This test only works when register allocation happens to use %rax for both ; load addresses. %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 { ; CHECK-LABEL: c_expand_expr_stmt: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: pushq %rbx ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: jne .LBB3_9 ; CHECK-NEXT: # %bb.1: # %entry ; CHECK-NEXT: movb 0, %bl ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: jne .LBB3_8 ; CHECK-NEXT: # %bb.2: # %bb.i ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: je .LBB3_8 ; CHECK-NEXT: # %bb.3: # %lvalue_p.exit ; CHECK-NEXT: movq 0, %rax ; CHECK-NEXT: movzbl (%rax), %ecx ; CHECK-NEXT: testl %ecx, %ecx ; CHECK-NEXT: je .LBB3_10 ; CHECK-NEXT: # %bb.4: # %lvalue_p.exit ; CHECK-NEXT: cmpl $2, %ecx ; CHECK-NEXT: jne .LBB3_15 ; CHECK-NEXT: # %bb.5: # %bb.i1 ; CHECK-NEXT: movq 32(%rax), %rax ; CHECK-NEXT: movzbl 16(%rax), %ecx ; CHECK-NEXT: testl %ecx, %ecx ; CHECK-NEXT: je .LBB3_13 ; CHECK-NEXT: # %bb.6: # %bb.i1 ; CHECK-NEXT: cmpl $2, %ecx ; CHECK-NEXT: jne .LBB3_15 ; CHECK-NEXT: # %bb.7: # %bb.i.i ; CHECK-NEXT: xorl %edi, %edi ; CHECK-NEXT: callq lvalue_p ; CHECK-NEXT: testl %eax, %eax ; CHECK-NEXT: setne %al ; CHECK-NEXT: jmp .LBB3_16 ; CHECK-NEXT: .LBB3_8: # %bb1 ; CHECK-NEXT: cmpb $23, %bl ; CHECK-NEXT: .LBB3_9: # %bb3 ; CHECK-NEXT: .LBB3_15: ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: .LBB3_16: # %lvalue_p.exit4 ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: jne .LBB3_9 ; CHECK-NEXT: # %bb.17: # %lvalue_p.exit4 ; CHECK-NEXT: testb %bl, %bl ; CHECK-NEXT: .LBB3_10: # %bb2.i3 ; CHECK-NEXT: movq 8(%rax), %rax ; CHECK-NEXT: movb 16(%rax), %cl ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: cmpb $23, %cl ; CHECK-NEXT: je .LBB3_16 ; CHECK-NEXT: # %bb.11: # %bb2.i3 ; CHECK-NEXT: cmpb $16, %cl ; CHECK-NEXT: je .LBB3_16 ; CHECK-NEXT: jmp .LBB3_9 ; CHECK-NEXT: .LBB3_13: # %bb2.i.i2 ; CHECK-NEXT: movq 8(%rax), %rax ; CHECK-NEXT: movb 16(%rax), %cl ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: cmpb $16, %cl ; CHECK-NEXT: je .LBB3_16 ; CHECK-NEXT: # %bb.14: # %bb2.i.i2 ; CHECK-NEXT: cmpb $23, %cl ; CHECK-NEXT: je .LBB3_16 ; CHECK-NEXT: jmp .LBB3_9 entry: %tmp4 = load i8, 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*, %union.tree_node** null, align 8 ; <%union.tree_node*> [#uses=3] %tmp22 = getelementptr inbounds %union.tree_node, %union.tree_node* %tmp21, i64 0, i32 0, i32 0, i64 0 ; [#uses=1] %tmp23 = load i8, 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, %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*, %union.tree_node** %tmp26, align 8 ; <%union.tree_node*> [#uses=2] %tmp28 = getelementptr inbounds %union.tree_node, %union.tree_node* %tmp27, i64 0, i32 0, i32 0, i64 16 ; [#uses=1] %tmp29 = load i8, 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, %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*, %union.tree_node** %tmp36, align 8 ; <%union.tree_node*> [#uses=1] %tmp38 = getelementptr inbounds %union.tree_node, %union.tree_node* %tmp37, i64 0, i32 0, i32 0, i64 16 ; [#uses=1] %tmp39 = load i8, 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, %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*, %union.tree_node** %tmp41, align 8 ; <%union.tree_node*> [#uses=1] %tmp43 = getelementptr inbounds %union.tree_node, %union.tree_node* %tmp42, i64 0, i32 0, i32 0, i64 16 ; [#uses=1] %tmp44 = load i8, 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. define dso_local void @foo(i1* %V) nounwind { ; CHECK-LABEL: foo: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: testq %rdi, %rdi ; CHECK-NEXT: je .LBB4_2 ; CHECK-NEXT: # %bb.1: # %bb ; CHECK-NEXT: pushq %rax ; CHECK-NEXT: callq func ; CHECK-NEXT: popq %rax ; CHECK-NEXT: .LBB4_2: # %return ; CHECK-NEXT: retq entry: %t0 = icmp eq i1* %V, null br i1 %t0, label %return, label %bb bb: call void @func() ret void return: ret void } declare dso_local void @func() ; one - One instruction may be tail-duplicated even with optsize. @XYZ = external dso_local global i32 declare dso_local void @tail_call_me() define dso_local void @one(i32 %v) nounwind optsize { ; CHECK-LABEL: one: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: testl %edi, %edi ; CHECK-NEXT: je .LBB5_3 ; CHECK-NEXT: # %bb.1: # %bby ; CHECK-NEXT: cmpl $16, %edi ; CHECK-NEXT: je .LBB5_4 ; CHECK-NEXT: # %bb.2: # %bb7 ; CHECK-NEXT: jmp tail_call_me # TAILCALL ; CHECK-NEXT: .LBB5_3: # %bbx ; CHECK-NEXT: cmpl $128, %edi ; CHECK-NEXT: jne tail_call_me # TAILCALL ; CHECK-NEXT: .LBB5_4: # %return ; CHECK-NEXT: retq entry: %0 = icmp eq i32 %v, 0 br i1 %0, label %bbx, label %bby bby: switch i32 %v, label %bb7 [ i32 16, label %return ] bb7: tail call void @tail_call_me() ret void bbx: switch i32 %v, label %bb12 [ i32 128, label %return ] bb12: tail call void @tail_call_me() ret void return: ret void } define dso_local void @one_pgso(i32 %v) nounwind !prof !14 { ; CHECK-LABEL: one_pgso: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: testl %edi, %edi ; CHECK-NEXT: je .LBB6_3 ; CHECK-NEXT: # %bb.1: # %bby ; CHECK-NEXT: cmpl $16, %edi ; CHECK-NEXT: je .LBB6_4 ; CHECK-NEXT: # %bb.2: # %bb7 ; CHECK-NEXT: jmp tail_call_me # TAILCALL ; CHECK-NEXT: .LBB6_3: # %bbx ; CHECK-NEXT: cmpl $128, %edi ; CHECK-NEXT: jne tail_call_me # TAILCALL ; CHECK-NEXT: .LBB6_4: # %return ; CHECK-NEXT: retq entry: %0 = icmp eq i32 %v, 0 br i1 %0, label %bbx, label %bby bby: switch i32 %v, label %bb7 [ i32 16, label %return ] bb7: tail call void @tail_call_me() ret void bbx: switch i32 %v, label %bb12 [ i32 128, label %return ] bb12: tail call void @tail_call_me() ret void 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. define dso_local void @two() nounwind optsize { ; CHECK-LABEL: two: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: je .LBB7_1 ; CHECK-NEXT: # %bb.2: # %return ; CHECK-NEXT: retq ; CHECK-NEXT: .LBB7_1: # %bb7 ; CHECK-NEXT: movl $0, {{.*}}(%rip) ; CHECK-NEXT: movl $1, {{.*}}(%rip) 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 } define dso_local void @two_pgso() nounwind !prof !14 { ; CHECK-LABEL: two_pgso: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: je .LBB8_1 ; CHECK-NEXT: # %bb.2: # %return ; CHECK-NEXT: retq ; CHECK-NEXT: .LBB8_1: # %bb7 ; CHECK-NEXT: movl $0, {{.*}}(%rip) ; CHECK-NEXT: movl $1, {{.*}}(%rip) 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_minsize - Same as two, but with minsize instead of optsize. define dso_local void @two_minsize() nounwind minsize { ; CHECK-LABEL: two_minsize: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: je .LBB9_1 ; CHECK-NEXT: # %bb.2: # %return ; CHECK-NEXT: retq ; CHECK-NEXT: .LBB9_1: # %bb7 ; CHECK-NEXT: movl $0, {{.*}}(%rip) ; CHECK-NEXT: movl $1, {{.*}}(%rip) 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. define dso_local void @two_nosize(i32 %x, i32 %y, i32 %z) nounwind { ; CHECK-LABEL: two_nosize: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: testl %edi, %edi ; CHECK-NEXT: je .LBB10_3 ; CHECK-NEXT: # %bb.1: # %bby ; CHECK-NEXT: testl %esi, %esi ; CHECK-NEXT: je .LBB10_4 ; CHECK-NEXT: # %bb.2: # %bb7 ; CHECK-NEXT: movl $0, {{.*}}(%rip) ; CHECK-NEXT: jmp tail_call_me # TAILCALL ; CHECK-NEXT: .LBB10_3: # %bbx ; CHECK-NEXT: cmpl $-1, %edx ; CHECK-NEXT: je .LBB10_4 ; CHECK-NEXT: # %bb.5: # %bb12 ; CHECK-NEXT: movl $0, {{.*}}(%rip) ; CHECK-NEXT: jmp tail_call_me # TAILCALL ; CHECK-NEXT: .LBB10_4: # %return ; CHECK-NEXT: retq entry: %0 = icmp eq i32 %x, 0 br i1 %0, label %bbx, label %bby bby: switch i32 %y, label %bb7 [ i32 0, label %return ] bb7: store volatile i32 0, i32* @XYZ tail call void @tail_call_me() ret void bbx: switch i32 %z, label %bb12 [ i32 -1, label %return ] bb12: store volatile i32 0, i32* @XYZ tail call void @tail_call_me() ret void 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. define i64 @TESTE(i64 %parami, i64 %paraml) nounwind readnone { ; CHECK-LABEL: TESTE: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: testq %rdi, %rdi ; CHECK-NEXT: movl $1, %eax ; CHECK-NEXT: cmovgq %rdi, %rax ; CHECK-NEXT: testq %rsi, %rsi ; CHECK-NEXT: jle .LBB11_2 ; CHECK-NEXT: # %bb.1: # %bb.nph ; CHECK-NEXT: imulq %rdi, %rsi ; CHECK-NEXT: movq %rsi, %rax ; CHECK-NEXT: .LBB11_2: # %for.end ; CHECK-NEXT: retq 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 } ; We should tail merge small blocks that don't end in a tail call or return ; instruction. Those blocks are typically unreachable and will be placed ; out-of-line after the main return, so we should try to eliminate as many of ; them as possible. declare dso_local void @abort() define dso_local void @merge_aborts() { ; CHECK-LABEL: merge_aborts: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: pushq %rax ; CHECK-NEXT: .cfi_def_cfa_offset 16 ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB12_5 ; CHECK-NEXT: # %bb.1: # %cont1 ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB12_5 ; CHECK-NEXT: # %bb.2: # %cont2 ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB12_5 ; CHECK-NEXT: # %bb.3: # %cont3 ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB12_5 ; CHECK-NEXT: # %bb.4: # %cont4 ; CHECK-NEXT: popq %rax ; CHECK-NEXT: .cfi_def_cfa_offset 8 ; CHECK-NEXT: retq ; CHECK-NEXT: .LBB12_5: # %abort1 ; CHECK-NEXT: .cfi_def_cfa_offset 16 ; CHECK-NEXT: callq abort entry: %c1 = call i1 @qux() br i1 %c1, label %cont1, label %abort1 abort1: call void @abort() unreachable cont1: %c2 = call i1 @qux() br i1 %c2, label %cont2, label %abort2 abort2: call void @abort() unreachable cont2: %c3 = call i1 @qux() br i1 %c3, label %cont3, label %abort3 abort3: call void @abort() unreachable cont3: %c4 = call i1 @qux() br i1 %c4, label %cont4, label %abort4 abort4: call void @abort() unreachable cont4: ret void } ; Use alternating abort functions so that the blocks we wish to merge are not ; layout successors during branch folding. declare dso_local void @alt_abort() define dso_local void @merge_alternating_aborts() { ; CHECK-LABEL: merge_alternating_aborts: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: pushq %rax ; CHECK-NEXT: .cfi_def_cfa_offset 16 ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB13_5 ; CHECK-NEXT: # %bb.1: # %cont1 ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB13_6 ; CHECK-NEXT: # %bb.2: # %cont2 ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB13_5 ; CHECK-NEXT: # %bb.3: # %cont3 ; CHECK-NEXT: callq qux ; CHECK-NEXT: testb $1, %al ; CHECK-NEXT: je .LBB13_6 ; CHECK-NEXT: # %bb.4: # %cont4 ; CHECK-NEXT: popq %rax ; CHECK-NEXT: .cfi_def_cfa_offset 8 ; CHECK-NEXT: retq ; CHECK-NEXT: .LBB13_5: # %abort1 ; CHECK-NEXT: .cfi_def_cfa_offset 16 ; CHECK-NEXT: callq abort ; CHECK-NEXT: .LBB13_6: # %abort2 ; CHECK-NEXT: callq alt_abort entry: %c1 = call i1 @qux() br i1 %c1, label %cont1, label %abort1 abort1: call void @abort() unreachable cont1: %c2 = call i1 @qux() br i1 %c2, label %cont2, label %abort2 abort2: call void @alt_abort() unreachable cont2: %c3 = call i1 @qux() br i1 %c3, label %cont3, label %abort3 abort3: call void @abort() unreachable cont3: %c4 = call i1 @qux() br i1 %c4, label %cont4, label %abort4 abort4: call void @alt_abort() unreachable cont4: ret void } ; This triggers a situation where a new block (bb4 is split) is created and then ; would be passed to the PGSO interface llvm::shouldOptimizeForSize(). @GV = dso_local global i32 0 define dso_local void @bfi_new_block_pgso(i32 %c) nounwind { ; CHECK-LABEL: bfi_new_block_pgso: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: testl %edi, %edi ; CHECK-NEXT: je .LBB14_4 ; CHECK-NEXT: # %bb.1: # %bb1 ; CHECK-NEXT: pushq %rax ; CHECK-NEXT: cmpl $16, %edi ; CHECK-NEXT: je .LBB14_6 ; CHECK-NEXT: # %bb.2: # %bb1 ; CHECK-NEXT: cmpl $17, %edi ; CHECK-NEXT: je .LBB14_7 ; CHECK-NEXT: # %bb.3: # %bb4 ; CHECK-NEXT: popq %rax ; CHECK-NEXT: jmp tail_call_me # TAILCALL ; CHECK-NEXT: .LBB14_4: # %bb5 ; CHECK-NEXT: cmpl $128, %edi ; CHECK-NEXT: jne .LBB14_8 ; CHECK-NEXT: # %bb.5: # %return ; CHECK-NEXT: retq ; CHECK-NEXT: .LBB14_6: # %bb3 ; CHECK-NEXT: movl $0, {{.*}}(%rip) ; CHECK-NEXT: .LBB14_7: # %bb4 ; CHECK-NEXT: callq func ; CHECK-NEXT: popq %rax ; CHECK-NEXT: .LBB14_8: # %bb6 ; CHECK-NEXT: jmp tail_call_me # TAILCALL entry: %0 = icmp eq i32 %c, 0 br i1 %0, label %bb5, label %bb1 bb1: switch i32 %c, label %bb4 [ i32 16, label %bb3 i32 17, label %bb2 ] bb2: call void @func() br label %bb4 bb3: store i32 0, i32* @GV call void @func() br label %bb4 bb4: tail call void @tail_call_me() br label %return bb5: switch i32 %c, label %bb6 [ i32 128, label %return ] bb6: tail call void @tail_call_me() br label %return return: ret void } !llvm.module.flags = !{!0} !0 = !{i32 1, !"ProfileSummary", !1} !1 = !{!2, !3, !4, !5, !6, !7, !8, !9} !2 = !{!"ProfileFormat", !"InstrProf"} !3 = !{!"TotalCount", i64 10000} !4 = !{!"MaxCount", i64 10} !5 = !{!"MaxInternalCount", i64 1} !6 = !{!"MaxFunctionCount", i64 1000} !7 = !{!"NumCounts", i64 3} !8 = !{!"NumFunctions", i64 3} !9 = !{!"DetailedSummary", !10} !10 = !{!11, !12, !13} !11 = !{i32 10000, i64 100, i32 1} !12 = !{i32 999000, i64 100, i32 1} !13 = !{i32 999999, i64 1, i32 2} !14 = !{!"function_entry_count", i64 0}