enhance vmcore to know that udiv's can be exact, and add a trivial

instcombine xform to exercise this.

Nothing forms exact udivs yet though.  This is progress on PR8862



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124992 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 27 insertions, 0 deletions

diff --git a/test/Assembler/flags.ll b/test/Assembler/flags.ll
index 3241909059..82b35b5c21 100644
--- a/test/Assembler/flags.ll
+++ b/test/Assembler/flags.ll
@@ -104,6 +104,19 @@ define i64 @sdiv_plain(i64 %x, i64 %y) {
 	ret i64 %z
 }
 
+define i64 @udiv_exact(i64 %x, i64 %y) {
+; CHECK: %z = udiv exact i64 %x, %y
+	%z = udiv exact i64 %x, %y
+	ret i64 %z
+}
+
+define i64 @udiv_plain(i64 %x, i64 %y) {
+; CHECK: %z = udiv i64 %x, %y
+	%z = udiv i64 %x, %y
+	ret i64 %z
+}
+
+
 define i64* @gep_nw(i64* %p, i64 %x) {
 ; CHECK: %z = getelementptr inbounds i64* %p, i64 %x
 	%z = getelementptr inbounds i64* %p, i64 %x
@@ -136,6 +149,11 @@ define i64 @sdiv_exact_ce() {
 	ret i64 sdiv exact (i64 ptrtoint (i64* @addr to i64), i64 91)
 }
 
+define i64 @udiv_exact_ce() {
+; CHECK: ret i64 udiv exact (i64 ptrtoint (i64* @addr to i64), i64 91)
+	ret i64 udiv exact (i64 ptrtoint (i64* @addr to i64), i64 91)
+}
+
 define i64* @gep_nw_ce() {
 ; CHECK: ret i64* getelementptr inbounds (i64* @addr, i64 171)
         ret i64* getelementptr inbounds (i64* @addr, i64 171)
@@ -210,3 +228,4 @@ define i64 @mul_unsigned_ce() {
 ; CHECK: ret i64 mul nuw (i64 ptrtoint (i64* @addr to i64), i64 91)
 	ret i64 mul nuw (i64 ptrtoint (i64* @addr to i64), i64 91)
 }
+
diff --git a/test/Transforms/InstCombine/exact-sdiv.ll b/test/Transforms/InstCombine/exact.ll
index e5677541e9..940469ea71 100644
--- a/test/Transforms/InstCombine/exact-sdiv.ll
+++ b/test/Transforms/InstCombine/exact.ll
@@ -50,3 +50,11 @@ define i32 @b1(i32 %x) {
   %z = mul i32 %y, -3
   ret i32 %z
 }
+
+; CHECK: i32 @b2
+; CHECK: ret i32 %x
+define i32 @b2(i32 %x, i32 %w) {
+  %y = udiv exact i32 %x, %w
+  %z = mul i32 %y, %w
+  ret i32 %z
+}