Fix bug in geometric last value (found with fuzz testing)
Rationale:
When power computation overflows, div should use 0 while mul should
use truncated version. Both cases were incorrectly using the latter.
Test: test-art-host
Bug: 34779592
Change-Id: I9eb8e1280c58b09d57886128f4df4541c143afaa
diff --git a/test/623-checker-loop-regressions/src/Main.java b/test/623-checker-loop-regressions/src/Main.java
index 7cc0b8b..7509d9b 100644
--- a/test/623-checker-loop-regressions/src/Main.java
+++ b/test/623-checker-loop-regressions/src/Main.java
@@ -154,8 +154,8 @@
/// CHECK-NOT: Phi
//
/// CHECK-START: int Main.polynomialInt() instruction_simplifier$after_bce (after)
- /// CHECK-DAG: <<Int:i\d+>> IntConstant -45 loop:none
- /// CHECK-DAG: Return [<<Int>>] loop:none
+ /// CHECK-DAG: <<Int:i\d+>> IntConstant -45 loop:none
+ /// CHECK-DAG: Return [<<Int>>] loop:none
static int polynomialInt() {
int x = 0;
for (int i = 0; i < 10; i++) {
@@ -164,6 +164,81 @@
return x;
}
+ // Regression test for b/34779592 (found with fuzz testing): overflow for last value
+ // of division truncates to zero, for multiplication it simply truncates.
+ //
+ /// CHECK-START: int Main.geoIntDivLastValue(int) loop_optimization (before)
+ /// CHECK-DAG: Phi loop:<<Loop:B\d+>> outer_loop:none
+ /// CHECK-DAG: Phi loop:<<Loop>> outer_loop:none
+ //
+ /// CHECK-START: int Main.geoIntDivLastValue(int) loop_optimization (after)
+ /// CHECK-NOT: Phi
+ //
+ /// CHECK-START: int Main.geoIntDivLastValue(int) instruction_simplifier$after_bce (after)
+ /// CHECK-DAG: <<Int:i\d+>> IntConstant 0 loop:none
+ /// CHECK-DAG: Return [<<Int>>] loop:none
+ static int geoIntDivLastValue(int x) {
+ for (int i = 0; i < 2; i++) {
+ x /= 1081788608;
+ }
+ return x;
+ }
+
+ /// CHECK-START: int Main.geoIntMulLastValue(int) loop_optimization (before)
+ /// CHECK-DAG: Phi loop:<<Loop:B\d+>> outer_loop:none
+ /// CHECK-DAG: Phi loop:<<Loop>> outer_loop:none
+ //
+ /// CHECK-START: int Main.geoIntMulLastValue(int) loop_optimization (after)
+ /// CHECK-NOT: Phi
+ //
+ /// CHECK-START: int Main.geoIntMulLastValue(int) instruction_simplifier$after_bce (after)
+ /// CHECK-DAG: <<Par:i\d+>> ParameterValue loop:none
+ /// CHECK-DAG: <<Int:i\d+>> IntConstant -194211840 loop:none
+ /// CHECK-DAG: <<Mul:i\d+>> Mul [<<Par>>,<<Int>>] loop:none
+ /// CHECK-DAG: Return [<<Mul>>] loop:none
+ static int geoIntMulLastValue(int x) {
+ for (int i = 0; i < 2; i++) {
+ x *= 1081788608;
+ }
+ return x;
+ }
+
+ /// CHECK-START: long Main.geoLongDivLastValue(long) loop_optimization (before)
+ /// CHECK-DAG: Phi loop:<<Loop:B\d+>> outer_loop:none
+ /// CHECK-DAG: Phi loop:<<Loop>> outer_loop:none
+ //
+ /// CHECK-START: long Main.geoLongDivLastValue(long) loop_optimization (after)
+ /// CHECK-NOT: Phi
+ //
+ /// CHECK-START: long Main.geoLongDivLastValue(long) instruction_simplifier$after_bce (after)
+ /// CHECK-DAG: <<Long:j\d+>> LongConstant 0 loop:none
+ /// CHECK-DAG: Return [<<Long>>] loop:none
+ static long geoLongDivLastValue(long x) {
+ for (int i = 0; i < 10; i++) {
+ x /= 1081788608;
+ }
+ return x;
+ }
+
+ /// CHECK-START: long Main.geoLongMulLastValue(long) loop_optimization (before)
+ /// CHECK-DAG: Phi loop:<<Loop:B\d+>> outer_loop:none
+ /// CHECK-DAG: Phi loop:<<Loop>> outer_loop:none
+ //
+ /// CHECK-START: long Main.geoLongMulLastValue(long) loop_optimization (after)
+ /// CHECK-NOT: Phi
+ //
+ /// CHECK-START: long Main.geoLongMulLastValue(long) instruction_simplifier$after_bce (after)
+ /// CHECK-DAG: <<Par:j\d+>> ParameterValue loop:none
+ /// CHECK-DAG: <<Long:j\d+>> LongConstant -8070450532247928832 loop:none
+ /// CHECK-DAG: <<Mul:j\d+>> Mul [<<Par>>,<<Long>>] loop:none
+ /// CHECK-DAG: Return [<<Mul>>] loop:none
+ static long geoLongMulLastValue(long x) {
+ for (int i = 0; i < 10; i++) {
+ x *= 1081788608;
+ }
+ return x;
+ }
+
public static void main(String[] args) {
expectEquals(10, earlyExitFirst(-1));
for (int i = 0; i <= 10; i++) {
@@ -185,6 +260,42 @@
expectEquals(-45, polynomialIntFromLong());
expectEquals(-45, polynomialInt());
+ expectEquals(0, geoIntDivLastValue(0));
+ expectEquals(0, geoIntDivLastValue(1));
+ expectEquals(0, geoIntDivLastValue(2));
+ expectEquals(0, geoIntDivLastValue(1081788608));
+ expectEquals(0, geoIntDivLastValue(-1081788608));
+ expectEquals(0, geoIntDivLastValue(2147483647));
+ expectEquals(0, geoIntDivLastValue(-2147483648));
+
+ expectEquals( 0, geoIntMulLastValue(0));
+ expectEquals( -194211840, geoIntMulLastValue(1));
+ expectEquals( -388423680, geoIntMulLastValue(2));
+ expectEquals(-1041498112, geoIntMulLastValue(1081788608));
+ expectEquals( 1041498112, geoIntMulLastValue(-1081788608));
+ expectEquals( 194211840, geoIntMulLastValue(2147483647));
+ expectEquals( 0, geoIntMulLastValue(-2147483648));
+
+ expectEquals(0L, geoLongDivLastValue(0L));
+ expectEquals(0L, geoLongDivLastValue(1L));
+ expectEquals(0L, geoLongDivLastValue(2L));
+ expectEquals(0L, geoLongDivLastValue(1081788608L));
+ expectEquals(0L, geoLongDivLastValue(-1081788608L));
+ expectEquals(0L, geoLongDivLastValue(2147483647L));
+ expectEquals(0L, geoLongDivLastValue(-2147483648L));
+ expectEquals(0L, geoLongDivLastValue(9223372036854775807L));
+ expectEquals(0L, geoLongDivLastValue(-9223372036854775808L));
+
+ expectEquals( 0L, geoLongMulLastValue(0L));
+ expectEquals(-8070450532247928832L, geoLongMulLastValue(1L));
+ expectEquals( 2305843009213693952L, geoLongMulLastValue(2L));
+ expectEquals( 0L, geoLongMulLastValue(1081788608L));
+ expectEquals( 0L, geoLongMulLastValue(-1081788608L));
+ expectEquals( 8070450532247928832L, geoLongMulLastValue(2147483647L));
+ expectEquals( 0L, geoLongMulLastValue(-2147483648L));
+ expectEquals( 8070450532247928832L, geoLongMulLastValue(9223372036854775807L));
+ expectEquals( 0L, geoLongMulLastValue(-9223372036854775808L));
+
System.out.println("passed");
}
@@ -193,4 +304,10 @@
throw new Error("Expected: " + expected + ", found: " + result);
}
}
+
+ private static void expectEquals(long expected, long result) {
+ if (expected != result) {
+ throw new Error("Expected: " + expected + ", found: " + result);
+ }
+ }
}