[AArch64][x86] add tests for unsigned subtract with overflow; NFC

llvm-svn: 353178

1 files changed, 197 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/AArch64/cgp-usubo.ll b/llvm/test/CodeGen/AArch64/cgp-usubo.ll
new file mode 100644
index 00000000000..1afa5858227
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/cgp-usubo.ll
@@ -0,0 +1,197 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=aarch64-- | FileCheck %s
+
+; CodeGenPrepare is expected to form overflow intrinsics to improve DAG/isel.
+
+define i1 @usubo_ult_i64(i64 %x, i64 %y, i64* %p) nounwind {
+; CHECK-LABEL: usubo_ult_i64:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    subs x8, x0, x1
+; CHECK-NEXT:    cset w0, lo
+; CHECK-NEXT:    str x8, [x2]
+; CHECK-NEXT:    ret
+  %s = sub i64 %x, %y
+  store i64 %s, i64* %p
+  %ov = icmp ult i64 %x, %y
+  ret i1 %ov
+}
+
+; Verify insertion point for single-BB. Toggle predicate.
+
+define i1 @usubo_ugt_i32(i32 %x, i32 %y, i32* %p) nounwind {
+; CHECK-LABEL: usubo_ugt_i32:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    cmp w1, w0
+; CHECK-NEXT:    cset w8, hi
+; CHECK-NEXT:    sub w9, w0, w1
+; CHECK-NEXT:    mov w0, w8
+; CHECK-NEXT:    str w9, [x2]
+; CHECK-NEXT:    ret
+  %ov = icmp ugt i32 %y, %x
+  %s = sub i32 %x, %y
+  store i32 %s, i32* %p
+  ret i1 %ov
+}
+
+; Constant operand should match.
+
+define i1 @usubo_ugt_constant_op0_i8(i8 %x, i8* %p) nounwind {
+; CHECK-LABEL: usubo_ugt_constant_op0_i8:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    and w8, w0, #0xff
+; CHECK-NEXT:    mov w9, #42
+; CHECK-NEXT:    cmp w8, #42 // =42
+; CHECK-NEXT:    sub w9, w9, w0
+; CHECK-NEXT:    cset w0, hi
+; CHECK-NEXT:    strb w9, [x1]
+; CHECK-NEXT:    ret
+  %s = sub i8 42, %x
+  %ov = icmp ugt i8 %x, 42
+  store i8 %s, i8* %p
+  ret i1 %ov
+}
+
+; Compare with constant operand 0 is canonicalized by commuting, but verify match for non-canonical form.
+
+define i1 @usubo_ult_constant_op0_i16(i16 %x, i16* %p) nounwind {
+; CHECK-LABEL: usubo_ult_constant_op0_i16:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    and w8, w0, #0xffff
+; CHECK-NEXT:    mov w9, #43
+; CHECK-NEXT:    cmp w8, #43 // =43
+; CHECK-NEXT:    sub w9, w9, w0
+; CHECK-NEXT:    cset w0, hi
+; CHECK-NEXT:    strh w9, [x1]
+; CHECK-NEXT:    ret
+  %s = sub i16 43, %x
+  %ov = icmp ult i16 43, %x
+  store i16 %s, i16* %p
+  ret i1 %ov
+}
+
+; Subtract with constant operand 1 is canonicalized to add.
+
+define i1 @usubo_ult_constant_op1_i16(i16 %x, i16* %p) nounwind {
+; CHECK-LABEL: usubo_ult_constant_op1_i16:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    and w8, w0, #0xffff
+; CHECK-NEXT:    cmp w8, #44 // =44
+; CHECK-NEXT:    sub w9, w0, #44 // =44
+; CHECK-NEXT:    cset w0, lo
+; CHECK-NEXT:    strh w9, [x1]
+; CHECK-NEXT:    ret
+  %s = add i16 %x, -44
+  %ov = icmp ult i16 %x, 44
+  store i16 %s, i16* %p
+  ret i1 %ov
+}
+
+define i1 @usubo_ugt_constant_op1_i8(i8 %x, i8* %p) nounwind {
+; CHECK-LABEL: usubo_ugt_constant_op1_i8:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    and w8, w0, #0xff
+; CHECK-NEXT:    cmp w8, #45 // =45
+; CHECK-NEXT:    cset w8, lo
+; CHECK-NEXT:    sub w9, w0, #45 // =45
+; CHECK-NEXT:    mov w0, w8
+; CHECK-NEXT:    strb w9, [x1]
+; CHECK-NEXT:    ret
+  %ov = icmp ugt i8 45, %x
+  %s = add i8 %x, -45
+  store i8 %s, i8* %p
+  ret i1 %ov
+}
+
+; Special-case: subtract 1 changes the compare predicate and constant.
+
+define i1 @usubo_eq_constant1_op1_i32(i32 %x, i32* %p) nounwind {
+; CHECK-LABEL: usubo_eq_constant1_op1_i32:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    cmp w0, #0 // =0
+; CHECK-NEXT:    sub w8, w0, #1 // =1
+; CHECK-NEXT:    cset w0, eq
+; CHECK-NEXT:    str w8, [x1]
+; CHECK-NEXT:    ret
+  %s = add i32 %x, -1
+  %ov = icmp eq i32 %x, 0
+  store i32 %s, i32* %p
+  ret i1 %ov
+}
+
+; Verify insertion point for multi-BB.
+
+declare void @call(i1)
+
+define i1 @usubo_ult_sub_dominates_i64(i64 %x, i64 %y, i64* %p, i1 %cond) nounwind {
+; CHECK-LABEL: usubo_ult_sub_dominates_i64:
+; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    tbz w3, #0, .LBB7_2
+; CHECK-NEXT:  // %bb.1: // %t
+; CHECK-NEXT:    subs x8, x0, x1
+; CHECK-NEXT:    cset w0, lo
+; CHECK-NEXT:    str x8, [x2]
+; CHECK-NEXT:    ret
+; CHECK-NEXT:  .LBB7_2: // %f
+; CHECK-NEXT:    and w0, w3, #0x1
+; CHECK-NEXT:    ret
+entry:
+  br i1 %cond, label %t, label %f
+
+t:
+  %s = sub i64 %x, %y
+  store i64 %s, i64* %p
+  br i1 %cond, label %end, label %f
+
+f:
+  ret i1 %cond
+
+end:
+  %ov = icmp ult i64 %x, %y
+  ret i1 %ov
+}
+
+define i1 @usubo_ult_cmp_dominates_i64(i64 %x, i64 %y, i64* %p, i1 %cond) nounwind {
+; CHECK-LABEL: usubo_ult_cmp_dominates_i64:
+; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    str x22, [sp, #-48]! // 8-byte Folded Spill
+; CHECK-NEXT:    stp x21, x20, [sp, #16] // 16-byte Folded Spill
+; CHECK-NEXT:    mov w20, w3
+; CHECK-NEXT:    stp x19, x30, [sp, #32] // 16-byte Folded Spill
+; CHECK-NEXT:    tbz w3, #0, .LBB8_3
+; CHECK-NEXT:  // %bb.1: // %t
+; CHECK-NEXT:    cmp x0, x1
+; CHECK-NEXT:    mov x22, x0
+; CHECK-NEXT:    cset w0, lo
+; CHECK-NEXT:    mov x19, x2
+; CHECK-NEXT:    mov x21, x1
+; CHECK-NEXT:    bl call
+; CHECK-NEXT:    subs x8, x22, x21
+; CHECK-NEXT:    b.hs .LBB8_3
+; CHECK-NEXT:  // %bb.2: // %end
+; CHECK-NEXT:    cset w0, lo
+; CHECK-NEXT:    str x8, [x19]
+; CHECK-NEXT:    b .LBB8_4
+; CHECK-NEXT:  .LBB8_3: // %f
+; CHECK-NEXT:    and w0, w20, #0x1
+; CHECK-NEXT:  .LBB8_4: // %f
+; CHECK-NEXT:    ldp x19, x30, [sp, #32] // 16-byte Folded Reload
+; CHECK-NEXT:    ldp x21, x20, [sp, #16] // 16-byte Folded Reload
+; CHECK-NEXT:    ldr x22, [sp], #48 // 8-byte Folded Reload
+; CHECK-NEXT:    ret
+entry:
+  br i1 %cond, label %t, label %f
+
+t:
+  %ov = icmp ult i64 %x, %y
+  call void @call(i1 %ov)
+  br i1 %ov, label %end, label %f
+
+f:
+  ret i1 %cond
+
+end:
+  %s = sub i64 %x, %y
+  store i64 %s, i64* %p
+  ret i1 %ov
+}
+