; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py ; RUN: llc < %s -mtriple=x86_64-linux-gnu | FileCheck %s ; fold (shl (zext (lshr (A, X))), X) -> (zext (shl (lshr (A, X)), X)) ; Canolicalize the sequence shl/zext/lshr performing the zeroextend ; as the last instruction of the sequence. ; This will help DAGCombiner to identify and then fold the sequence ; of shifts into a single AND. ; This transformation is profitable if the shift amounts are the same ; and if there is only one use of the zext. define i16 @fun1(i8 zeroext %v) { ; CHECK-LABEL: fun1: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: movl %edi, %eax ; CHECK-NEXT: andl $-16, %eax ; CHECK-NEXT: # kill: def $ax killed $ax killed $eax ; CHECK-NEXT: retq entry: %shr = lshr i8 %v, 4 %ext = zext i8 %shr to i16 %shl = shl i16 %ext, 4 ret i16 %shl } define i32 @fun2(i8 zeroext %v) { ; CHECK-LABEL: fun2: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: movl %edi, %eax ; CHECK-NEXT: andl $-16, %eax ; CHECK-NEXT: retq entry: %shr = lshr i8 %v, 4 %ext = zext i8 %shr to i32 %shl = shl i32 %ext, 4 ret i32 %shl } define i32 @fun3(i16 zeroext %v) { ; CHECK-LABEL: fun3: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: movl %edi, %eax ; CHECK-NEXT: andl $-16, %eax ; CHECK-NEXT: retq entry: %shr = lshr i16 %v, 4 %ext = zext i16 %shr to i32 %shl = shl i32 %ext, 4 ret i32 %shl } define i64 @fun4(i8 zeroext %v) { ; CHECK-LABEL: fun4: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: movl %edi, %eax ; CHECK-NEXT: andl $-16, %eax ; CHECK-NEXT: retq entry: %shr = lshr i8 %v, 4 %ext = zext i8 %shr to i64 %shl = shl i64 %ext, 4 ret i64 %shl } define i64 @fun5(i16 zeroext %v) { ; CHECK-LABEL: fun5: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: movl %edi, %eax ; CHECK-NEXT: andl $-16, %eax ; CHECK-NEXT: retq entry: %shr = lshr i16 %v, 4 %ext = zext i16 %shr to i64 %shl = shl i64 %ext, 4 ret i64 %shl } define i64 @fun6(i32 zeroext %v) { ; CHECK-LABEL: fun6: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: movl %edi, %eax ; CHECK-NEXT: andl $-16, %eax ; CHECK-NEXT: retq entry: %shr = lshr i32 %v, 4 %ext = zext i32 %shr to i64 %shl = shl i64 %ext, 4 ret i64 %shl } ; Don't fold the pattern if we use arithmetic shifts. define i64 @fun7(i8 zeroext %v) { ; CHECK-LABEL: fun7: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: sarb $4, %dil ; CHECK-NEXT: movzbl %dil, %eax ; CHECK-NEXT: shlq $4, %rax ; CHECK-NEXT: retq entry: %shr = ashr i8 %v, 4 %ext = zext i8 %shr to i64 %shl = shl i64 %ext, 4 ret i64 %shl } define i64 @fun8(i16 zeroext %v) { ; CHECK-LABEL: fun8: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: movswl %di, %eax ; CHECK-NEXT: shrl $4, %eax ; CHECK-NEXT: movzwl %ax, %eax ; CHECK-NEXT: shlq $4, %rax ; CHECK-NEXT: retq entry: %shr = ashr i16 %v, 4 %ext = zext i16 %shr to i64 %shl = shl i64 %ext, 4 ret i64 %shl } define i64 @fun9(i32 zeroext %v) { ; CHECK-LABEL: fun9: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: movl %edi, %eax ; CHECK-NEXT: sarl $4, %eax ; CHECK-NEXT: shlq $4, %rax ; CHECK-NEXT: retq entry: %shr = ashr i32 %v, 4 %ext = zext i32 %shr to i64 %shl = shl i64 %ext, 4 ret i64 %shl } ; Don't fold the pattern if there is more than one use of the ; operand in input to the shift left. define i64 @fun10(i8 zeroext %v) { ; CHECK-LABEL: fun10: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: shrb $4, %dil ; CHECK-NEXT: movzbl %dil, %ecx ; CHECK-NEXT: movq %rcx, %rax ; CHECK-NEXT: shlq $4, %rax ; CHECK-NEXT: orq %rcx, %rax ; CHECK-NEXT: retq entry: %shr = lshr i8 %v, 4 %ext = zext i8 %shr to i64 %shl = shl i64 %ext, 4 %add = add i64 %shl, %ext ret i64 %add } define i64 @fun11(i16 zeroext %v) { ; CHECK-LABEL: fun11: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: # kill: def $edi killed $edi def $rdi ; CHECK-NEXT: shrl $4, %edi ; CHECK-NEXT: movq %rdi, %rax ; CHECK-NEXT: shlq $4, %rax ; CHECK-NEXT: addq %rdi, %rax ; CHECK-NEXT: retq entry: %shr = lshr i16 %v, 4 %ext = zext i16 %shr to i64 %shl = shl i64 %ext, 4 %add = add i64 %shl, %ext ret i64 %add } define i64 @fun12(i32 zeroext %v) { ; CHECK-LABEL: fun12: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: # kill: def $edi killed $edi def $rdi ; CHECK-NEXT: shrl $4, %edi ; CHECK-NEXT: movq %rdi, %rax ; CHECK-NEXT: shlq $4, %rax ; CHECK-NEXT: addq %rdi, %rax ; CHECK-NEXT: retq entry: %shr = lshr i32 %v, 4 %ext = zext i32 %shr to i64 %shl = shl i64 %ext, 4 %add = add i64 %shl, %ext ret i64 %add } ; PR17380 ; Make sure that the combined dags are legal if we run the DAGCombiner after ; Legalization took place. The add instruction is redundant and increases by ; one the number of uses of the zext. This prevents the transformation from ; firing before dags are legalized and optimized. ; Once the add is removed, the number of uses becomes one and therefore the ; dags are canonicalized. After Legalization, we need to make sure that the ; valuetype for the shift count is legal. ; Verify also that we correctly fold the shl-shr sequence into an ; AND with bitmask. define void @g(i32 %a) { ; CHECK-LABEL: g: ; CHECK: # %bb.0: ; CHECK-NEXT: # kill: def $edi killed $edi def $rdi ; CHECK-NEXT: andl $-4, %edi ; CHECK-NEXT: jmp f # TAILCALL %b = lshr i32 %a, 2 %c = zext i32 %b to i64 %d = add i64 %c, 1 %e = shl i64 %c, 2 tail call void @f(i64 %e) ret void } declare dso_local void @f(i64)