[llvm] [InstCombine] Fold expression using basic properties of floor and ceiling function (PR #107107)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,194 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+define i1 @floor_x_ole(float %x) {
+; CHECK-LABEL: @floor_x_ole(
+; CHECK-NEXT:    [[RET:%.*]] = fcmp ninf ord float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %floor = call float @llvm.floor.f32(float %x)
+  %ret = fcmp ninf ole float %floor, %x
+  ret i1 %ret
+}
+
+define i1 @floor_x_ule(float %x) {
+; CHECK-LABEL: @floor_x_ule(
+; CHECK-NEXT:    ret i1 true
+;
+  %floor = call float @llvm.floor.f32(float %x)
+  %ret = fcmp ule float %floor, %x
+  ret i1 %ret
+}
+
+define i1 @floor_x_ogt(float %x) {
+; CHECK-LABEL: @floor_x_ogt(
+; CHECK-NEXT:    ret i1 false
+;
+  %floor = call float @llvm.floor.f32(float %x)
+  %ret = fcmp ogt float %floor, %x
+  ret i1 %ret
+}
+
+define i1 @floor_x_ugt(float %x) {
+; CHECK-LABEL: @floor_x_ugt(
+; CHECK-NEXT:    [[RET:%.*]] = fcmp uno float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %floor = call float @llvm.floor.f32(float %x)
+  %ret = fcmp ugt float %floor, %x
+  ret i1 %ret
+}
+
+define i1 @x_floor_oge(float %x) {
+; CHECK-LABEL: @x_floor_oge(
+; CHECK-NEXT:    [[RET:%.*]] = fcmp ord float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %floor = call float @llvm.floor.f32(float %x)
+  %ret = fcmp oge float %x, %floor
+  ret i1 %ret
+}
+
+define i1 @x_floor_uge(float %x) {
+; CHECK-LABEL: @x_floor_uge(
+; CHECK-NEXT:    ret i1 true
+;
+  %floor = call float @llvm.floor.f32(float %x)
+  %ret = fcmp uge float %x, %floor
+  ret i1 %ret
+}
+
+define i1 @x_floor_olt(float %x) {
+; CHECK-LABEL: @x_floor_olt(
+; CHECK-NEXT:    ret i1 false
+;
+  %floor = call float @llvm.floor.f32(float %x)
+  %ret = fcmp olt float %x, %floor
+  ret i1 %ret
+}
+
+define i1 @x_floor_ult(float %x) {
+; CHECK-LABEL: @x_floor_ult(
+; CHECK-NEXT:    [[RET:%.*]] = fcmp uno float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %floor = call float @llvm.floor.f32(float %x)
+  %ret = fcmp ult float %x, %floor
+  ret i1 %ret
+}
+
+define <2 x i1> @x_floor_olt_vec(<2 x float> %x) {
+; CHECK-LABEL: @x_floor_olt_vec(
+; CHECK-NEXT:    ret <2 x i1> zeroinitializer
+;
+  %floor = call <2 x float> @llvm.floor.f32(<2 x float> %x)
+  %ret = fcmp olt <2 x float> %x, %floor
+  ret <2 x i1> %ret
+}
+
+define i1 @x_floor_ole_neg(float %x) {
+; CHECK-LABEL: @x_floor_ole_neg(
+; CHECK-NEXT:    [[FLOOR:%.*]] = call float @llvm.floor.f32(float [[X:%.*]])
+; CHECK-NEXT:    [[RET:%.*]] = fcmp ole float [[X]], [[FLOOR]]
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %floor = call float @llvm.floor.f32(float %x)
+  %ret = fcmp ole float %x, %floor
+  ret i1 %ret
+}
+
+define i1 @ceil_x_oge(float %x) {
+; CHECK-LABEL: @ceil_x_oge(
+; CHECK-NEXT:    [[RET:%.*]] = fcmp ninf ord float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %ceil = call float @llvm.ceil.f32(float %x)
+  %ret = fcmp ninf oge float %ceil, %x
+  ret i1 %ret
+}
+
+define i1 @ceil_x_uge(float %x) {
+; CHECK-LABEL: @ceil_x_uge(
+; CHECK-NEXT:    ret i1 true
+;
+  %ceil = call float @llvm.ceil.f32(float %x)
+  %ret = fcmp uge float %ceil, %x
+  ret i1 %ret
+}
+
+define i1 @ceil_x_olt(float %x) {
+; CHECK-LABEL: @ceil_x_olt(
+; CHECK-NEXT:    ret i1 false
+;
+  %ceil = call float @llvm.ceil.f32(float %x)
+  %ret = fcmp olt float %ceil, %x
+  ret i1 %ret
+}
+
+define i1 @ceil_x_ult(float %x) {
+; CHECK-LABEL: @ceil_x_ult(
+; CHECK-NEXT:    [[RET:%.*]] = fcmp uno float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %ceil = call float @llvm.ceil.f32(float %x)
+  %ret = fcmp ult float %ceil, %x
+  ret i1 %ret
+}
+
+define i1 @x_ceil_ole(float %x) {
+; CHECK-LABEL: @x_ceil_ole(
+; CHECK-NEXT:    [[RET:%.*]] = fcmp ord float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %ceil = call float @llvm.ceil.f32(float %x)
+  %ret = fcmp ole float %x, %ceil
+  ret i1 %ret
+}
+
+define i1 @x_ceil_ule(float %x) {
+; CHECK-LABEL: @x_ceil_ule(
+; CHECK-NEXT:    ret i1 true
+;
+  %ceil = call float @llvm.ceil.f32(float %x)
+  %ret = fcmp ule float %x, %ceil
+  ret i1 %ret
+}
+
+define i1 @x_ceil_ogt(float %x) {
+; CHECK-LABEL: @x_ceil_ogt(
+; CHECK-NEXT:    ret i1 false
+;
+  %ceil = call float @llvm.ceil.f32(float %x)
+  %ret = fcmp ogt float %x, %ceil
+  ret i1 %ret
+}
+
+define i1 @x_ceil_ugt(float %x) {
+; CHECK-LABEL: @x_ceil_ugt(
+; CHECK-NEXT:    [[RET:%.*]] = fcmp uno float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %ceil = call float @llvm.ceil.f32(float %x)
+  %ret = fcmp ugt float %x, %ceil
+  ret i1 %ret
+}
+
+define <2 x i1> @x_ceil_ogt_vec(<2 x float> %x) {
+; CHECK-LABEL: @x_ceil_ogt_vec(
+; CHECK-NEXT:    ret <2 x i1> zeroinitializer
+;
+  %ceil = call <2 x float> @llvm.ceil.f32(<2 x float> %x)
+  %ret = fcmp ogt <2 x float> %x, %ceil
+  ret <2 x i1> %ret
+}
+
+define i1 @x_ceil_oge_neg(float %x) {
+; CHECK-LABEL: @x_ceil_oge_neg(
+; CHECK-NEXT:    [[CEIL:%.*]] = call float @llvm.ceil.f32(float [[X:%.*]])
+; CHECK-NEXT:    [[RET:%.*]] = fcmp oge float [[X]], [[CEIL]]
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %ceil = call float @llvm.ceil.f32(float %x)
+  %ret = fcmp oge float %x, %ceil
+  ret i1 %ret
+}
----------------
arsenm wrote:

Negative tests for the other compare types, like oeq/one/une/ord/uno 

https://github.com/llvm/llvm-project/pull/107107