[llvm] [InstCombine] simplify `(X * C0) / (X * C1)` into `C0 / C1`. (PR #73204)
Yingwei Zheng via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 28 22:35:40 PST 2023
================
@@ -1432,6 +1432,224 @@ define <2 x i8> @sdiv_sdiv_mul_nsw(<2 x i8> %x, <2 x i8> %y, <2 x i8> %z) {
ret <2 x i8> %r
}
+; (X * C0) / (X * C1) --> C0 / C1
+define i8 @sdiv_mul_nsw_mul(i8 %x,i8 %y,i8 %z) {
+; CHECK-LABEL: @sdiv_mul_nsw_mul(
+; CHECK-NEXT: [[ADD4:%.*]] = mul i8 [[X:%.*]], [[Z:%.*]]
+; CHECK-NEXT: [[ADD5:%.*]] = mul nsw i8 [[X]], [[Y:%.*]]
+; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul i8 %x, %z
+ %add5 = mul nsw i8 %x, %y
+ %div = sdiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @sdiv_mul_nsw_mul_nsw(i8 %x,i8 %y,i8 %z) {
+; CHECK-LABEL: @sdiv_mul_nsw_mul_nsw(
+; CHECK-NEXT: [[ADD4:%.*]] = mul nsw i8 [[X:%.*]], [[Z:%.*]]
+; CHECK-NEXT: [[ADD5:%.*]] = mul nsw i8 [[X]], [[Y:%.*]]
+; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul nsw i8 %x, %z
+ %add5 = mul nsw i8 %x, %y
+ %div = sdiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @sdiv_mul_mul_nsw(i8 %x,i8 %y,i8 %z) {
+; CHECK-LABEL: @sdiv_mul_mul_nsw(
+; CHECK-NEXT: [[ADD4:%.*]] = mul nsw i8 [[X:%.*]], [[Z:%.*]]
+; CHECK-NEXT: [[ADD5:%.*]] = mul i8 [[X]], [[Y:%.*]]
+; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul nsw i8 %x, %z
+ %add5 = mul i8 %x, %y
+ %div = sdiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @sdiv_mul_mul(i8 %x,i8 %y,i8 %z) {
+; CHECK-LABEL: @sdiv_mul_mul(
+; CHECK-NEXT: [[ADD4:%.*]] = mul i8 [[X:%.*]], [[Z:%.*]]
+; CHECK-NEXT: [[ADD5:%.*]] = mul i8 [[X]], [[Y:%.*]]
+; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul i8 %x, %z
+ %add5 = mul i8 %x, %y
+ %div = sdiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @udiv_mul_mul(i8 %x,i8 %y,i8 %z) {
+; CHECK-LABEL: @udiv_mul_mul(
+; CHECK-NEXT: [[ADD4:%.*]] = mul i8 [[X:%.*]], [[Z:%.*]]
+; CHECK-NEXT: [[ADD5:%.*]] = mul i8 [[X]], [[Y:%.*]]
+; CHECK-NEXT: [[DIV:%.*]] = udiv i8 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul i8 %x, %z
+ %add5 = mul i8 %x, %y
+ %div = udiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @udiv_mul_nuw_mul_nuw(i8 %x,i8 %y,i8 %z) {
+; CHECK-LABEL: @udiv_mul_nuw_mul_nuw(
+; CHECK-NEXT: [[DIV:%.*]] = udiv i8 [[Y:%.*]], [[Z:%.*]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul nuw i8 %x, %z
+ %add5 = mul nuw i8 %x, %y
+ %div = udiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @udiv_mul_mul_nuw(i8 %x,i8 %y,i8 %z) {
+; CHECK-LABEL: @udiv_mul_mul_nuw(
+; CHECK-NEXT: [[ADD4:%.*]] = mul nuw i8 [[X:%.*]], [[Z:%.*]]
+; CHECK-NEXT: [[ADD5:%.*]] = mul i8 [[X]], [[Y:%.*]]
+; CHECK-NEXT: [[DIV:%.*]] = udiv i8 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul nuw i8 %x, %z
+ %add5 = mul i8 %x, %y
+ %div = udiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @udiv_mul_nuw_mul(i8 %x,i8 %y,i8 %z) {
+; CHECK-LABEL: @udiv_mul_nuw_mul(
+; CHECK-NEXT: [[ADD4:%.*]] = mul i8 [[X:%.*]], [[Z:%.*]]
+; CHECK-NEXT: [[ADD5:%.*]] = mul nuw i8 [[X]], [[Y:%.*]]
+; CHECK-NEXT: [[DIV:%.*]] = udiv i8 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul i8 %x, %z
+ %add5 = mul nuw i8 %x, %y
+ %div = udiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @sdiv_mul_nsw_constant_mul_constant(i8 %x) {
+; CHECK-LABEL: @sdiv_mul_nsw_constant_mul_constant(
+; CHECK-NEXT: ret i8 2
+;
+ %add4 = mul i8 %x, 6
+ %add5 = mul nsw i8 %x, 12
+ %div = sdiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @sdiv_mul_nsw_constant_mul_nsw_constant(i8 %x) {
+; CHECK-LABEL: @sdiv_mul_nsw_constant_mul_nsw_constant(
+; CHECK-NEXT: ret i8 2
+;
+ %add4 = mul nsw i8 %x, 5
+ %add5 = mul nsw i8 %x, 10
+ %div = sdiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @sdiv_mul_constant_mul_nsw_constant(i8 %x) {
+; CHECK-LABEL: @sdiv_mul_constant_mul_nsw_constant(
+; CHECK-NEXT: [[ADD4:%.*]] = mul nsw i8 [[X:%.*]], 10
+; CHECK-NEXT: [[ADD5:%.*]] = mul i8 [[X]], 20
+; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul nsw i8 %x, 10
+ %add5 = mul i8 %x, 20
+ %div = sdiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @sdiv_mul_constant_mul_constant(i8 %x) {
+; CHECK-LABEL: @sdiv_mul_constant_mul_constant(
+; CHECK-NEXT: [[ADD4:%.*]] = mul i8 [[X:%.*]], 10
+; CHECK-NEXT: [[ADD5:%.*]] = mul i8 [[X]], 20
+; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul i8 %x, 10
+ %add5 = mul i8 %x, 20
+ %div = sdiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @udiv_mul_constant_mul_constant(i8 %x) {
+; CHECK-LABEL: @udiv_mul_constant_mul_constant(
+; CHECK-NEXT: [[ADD4:%.*]] = mul i8 [[X:%.*]], 10
+; CHECK-NEXT: [[ADD5:%.*]] = mul i8 [[X]], 20
+; CHECK-NEXT: [[DIV:%.*]] = udiv i8 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul i8 %x, 10
+ %add5 = mul i8 %x, 20
+ %div = udiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @udiv_mul_nuw_constant_mul_nuw_constant(i8 %x) {
+; CHECK-LABEL: @udiv_mul_nuw_constant_mul_nuw_constant(
+; CHECK-NEXT: ret i8 1
+;
+ %add4 = mul nuw i8 %x, 10
+ %add5 = mul nuw i8 %x, 10
+ %div = udiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @udiv_mul_constant_mul_nuw_constant(i8 %x) {
+; CHECK-LABEL: @udiv_mul_constant_mul_nuw_constant(
+; CHECK-NEXT: [[ADD4:%.*]] = mul nuw i8 [[X:%.*]], 10
+; CHECK-NEXT: [[ADD5:%.*]] = mul i8 [[X]], 20
+; CHECK-NEXT: [[DIV:%.*]] = udiv i8 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i8 [[DIV]]
+;
+ %add4 = mul nuw i8 %x, 10
+ %add5 = mul i8 %x, 20
+ %div = udiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i8 @udiv_mul_constant_nuw_mul_constant(i8 %x) {
+; CHECK-LABEL: @udiv_mul_constant_nuw_mul_constant(
+; CHECK-NEXT: ret i8 2
+;
+ %add4 = mul i8 %x, 10
+ %add5 = mul nuw i8 %x, 20
+ %div = udiv i8 %add5, %add4
+ ret i8 %div
+}
+
+define i4 @sdiv_mul_nsw_mul_nsw_allones(i4 %a, i4 %c2) {
+; CHECK-LABEL: @sdiv_mul_nsw_mul_nsw_allones(
+; CHECK-NEXT: [[ADD4:%.*]] = sub nsw i4 0, [[A:%.*]]
+; CHECK-NEXT: [[ADD5:%.*]] = mul nsw i4 [[A]], [[C2:%.*]]
+; CHECK-NEXT: [[DIV:%.*]] = sdiv i4 [[ADD5]], [[ADD4]]
+; CHECK-NEXT: ret i4 [[DIV]]
+;
+ %add4 = mul nsw i4 %a, -1
+ %add5 = mul nsw i4 %a, %c2
+ %div = sdiv i4 %add5, %add4
+ ret i4 %div
+}
+
+define i4 @sdiv_mul_nsw_mul_signmask(i4 %a, i4 %c2) {
+; CHECK-LABEL: @sdiv_mul_nsw_mul_signmask(
+; CHECK-NEXT: ret i4 poison
+;
+ %add4 = mul nsw i4 %a, 64
----------------
dtcxzyw wrote:
```suggestion
%add4 = mul nsw i4 %a, -8
```
https://github.com/llvm/llvm-project/pull/73204
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