diff options
| -rw-r--r-- | llvm/test/Transforms/InstCombine/mul.ll | 61 |
1 files changed, 53 insertions, 8 deletions
diff --git a/llvm/test/Transforms/InstCombine/mul.ll b/llvm/test/Transforms/InstCombine/mul.ll index e56f36a..64ed57e 100644 --- a/llvm/test/Transforms/InstCombine/mul.ll +++ b/llvm/test/Transforms/InstCombine/mul.ll @@ -38,6 +38,9 @@ define i32 @neg(i32 %i) { ret i32 %tmp } +; Use the sign-bit as a mask: +; (zext (A < 0)) * B --> (A >> 31) & B + define i32 @test10(i32 %a, i32 %b) { ; CHECK-LABEL: @test10( ; CHECK-NEXT: [[TMP1:%.*]] = ashr i32 [[A:%.*]], 31 @@ -46,7 +49,6 @@ define i32 @test10(i32 %a, i32 %b) { ; %c = icmp slt i32 %a, 0 %d = zext i1 %c to i32 - ; e = b & (a >> 31) %e = mul i32 %d, %b ret i32 %e } @@ -59,20 +61,24 @@ define i32 @test11(i32 %a, i32 %b) { ; %c = icmp sle i32 %a, -1 %d = zext i1 %c to i32 - ; e = b & (a >> 31) %e = mul i32 %d, %b ret i32 %e } +declare void @use32(i32) + define i32 @test12(i32 %a, i32 %b) { ; CHECK-LABEL: @test12( -; CHECK-NEXT: [[TMP1:%.*]] = ashr i32 [[A:%.*]], 31 +; CHECK-NEXT: [[A_LOBIT:%.*]] = lshr i32 [[A:%.*]], 31 +; CHECK-NEXT: [[TMP1:%.*]] = ashr i32 [[A]], 31 ; CHECK-NEXT: [[E:%.*]] = and i32 [[TMP1]], [[B:%.*]] +; CHECK-NEXT: call void @use32(i32 [[A_LOBIT]]) ; CHECK-NEXT: ret i32 [[E]] ; %c = icmp ugt i32 %a, 2147483647 %d = zext i1 %c to i32 %e = mul i32 %d, %b + call void @use32(i32 %d) ret i32 %e } @@ -121,18 +127,57 @@ define <2 x i32> @mul_bool_vec_commute(<2 x i32> %x, <2 x i1> %y) { ret <2 x i32> %m } -; X * Y (when Y is 0 or 1) --> x & (0-Y) -define i32 @test17(i32 %a, i32 %b) { -; CHECK-LABEL: @test17( +; (A >>u 31) * B --> (A >>s 31) & B + +define i32 @signbit_mul(i32 %a, i32 %b) { +; CHECK-LABEL: @signbit_mul( ; CHECK-NEXT: [[TMP1:%.*]] = ashr i32 [[A:%.*]], 31 ; CHECK-NEXT: [[E:%.*]] = and i32 [[TMP1]], [[B:%.*]] ; CHECK-NEXT: ret i32 [[E]] ; - %a.lobit = lshr i32 %a, 31 - %e = mul i32 %a.lobit, %b + %d = lshr i32 %a, 31 + %e = mul i32 %d, %b + ret i32 %e +} + +define i32 @signbit_mul_commute_extra_use(i32 %a, i32 %b) { +; CHECK-LABEL: @signbit_mul_commute_extra_use( +; CHECK-NEXT: [[D:%.*]] = lshr i32 [[A:%.*]], 31 +; CHECK-NEXT: [[TMP1:%.*]] = ashr i32 [[A]], 31 +; CHECK-NEXT: [[E:%.*]] = and i32 [[TMP1]], [[B:%.*]] +; CHECK-NEXT: call void @use32(i32 [[D]]) +; CHECK-NEXT: ret i32 [[E]] +; + %d = lshr i32 %a, 31 + %e = mul i32 %b, %d + call void @use32(i32 %d) ret i32 %e } +; (A >>u 31)) * B --> (A >>s 31) & B + +define <2 x i32> @signbit_mul_vec(<2 x i32> %a, <2 x i32> %b) { +; CHECK-LABEL: @signbit_mul_vec( +; CHECK-NEXT: [[D:%.*]] = lshr <2 x i32> [[A:%.*]], <i32 31, i32 31> +; CHECK-NEXT: [[E:%.*]] = mul nuw <2 x i32> [[D]], [[B:%.*]] +; CHECK-NEXT: ret <2 x i32> [[E]] +; + %d = lshr <2 x i32> %a, <i32 31, i32 31> + %e = mul <2 x i32> %d, %b + ret <2 x i32> %e +} + +define <2 x i32> @signbit_mul_vec_commute(<2 x i32> %a, <2 x i32> %b) { +; CHECK-LABEL: @signbit_mul_vec_commute( +; CHECK-NEXT: [[D:%.*]] = lshr <2 x i32> [[A:%.*]], <i32 31, i32 31> +; CHECK-NEXT: [[E:%.*]] = mul nuw <2 x i32> [[D]], [[B:%.*]] +; CHECK-NEXT: ret <2 x i32> [[E]] +; + %d = lshr <2 x i32> %a, <i32 31, i32 31> + %e = mul <2 x i32> %b, %d + ret <2 x i32> %e +} + define i32 @test18(i32 %A, i32 %B) { ; CHECK-LABEL: @test18( ; CHECK-NEXT: ret i32 0 |