[llvm] [ConstantFold] Fold `erf` and `erff` when the input parameter is a constant value. (PR #113079)

[Matt Arsenault via llvm-commits]

================
@@ -0,0 +1,185 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=instcombine -mtriple x86_64-unknown-linux-gnu -S | FileCheck %s
+
+define float @erff_const() {
+; CHECK-LABEL: define float @erff_const() {
+; CHECK-NEXT:    [[R:%.*]] = call float @erff(float 5.000000e-01)
+; CHECK-NEXT:    ret float 0x3FE0A7EF60000000
+;
+  %r = call float @erff(float 5.000000e-01)
+  ret float %r
+}
+
+define double @erf_const() {
+; CHECK-LABEL: define double @erf_const() {
+; CHECK-NEXT:    [[R:%.*]] = call double @erf(double -5.000000e-01)
+; CHECK-NEXT:    ret double 0xBFE0A7EF5C18EDD2
+;
+  %r = call double @erf(double -5.000000e-01)
+  ret double %r
+}
+
+define float @erff_zero() {
+; CHECK-LABEL: define float @erff_zero() {
+; CHECK-NEXT:    [[R:%.*]] = call float @erff(float 0.000000e+00)
+; CHECK-NEXT:    ret float 0.000000e+00
+;
+  %r = call float @erff(float 0.000000e+00)
+  ret float %r
+}
+
+define double @erf_zero() {
+; CHECK-LABEL: define double @erf_zero() {
+; CHECK-NEXT:    [[R:%.*]] = call double @erf(double 0.000000e+00)
+; CHECK-NEXT:    ret double 0.000000e+00
+;
+  %r = call double @erf(double 0.000000e+00)
+  ret double %r
+}
+
+define float @erff_neg_zero() {
+; CHECK-LABEL: define float @erff_neg_zero() {
+; CHECK-NEXT:    [[R:%.*]] = call float @erff(float -0.000000e+00)
+; CHECK-NEXT:    ret float -0.000000e+00
+;
+  %r = call float @erff(float -0.000000e+00)
+  ret float %r
+}
+
+define double @erf_neg_zero() {
+; CHECK-LABEL: define double @erf_neg_zero() {
+; CHECK-NEXT:    [[R:%.*]] = call double @erf(double -0.000000e+00)
+; CHECK-NEXT:    ret double -0.000000e+00
+;
+  %r = call double @erf(double -0.000000e+00)
+  ret double %r
+}
+
+define float @erff_inf() {
+; CHECK-LABEL: define float @erff_inf() {
+; CHECK-NEXT:    [[R:%.*]] = call float @erff(float 0x7FF0000000000000)
+; CHECK-NEXT:    ret float [[R]]
+;
+  %r = call float @erff(float 0x7FF0000000000000)
+  ret float %r
+}
+
+define double @erf_inf() {
+; CHECK-LABEL: define double @erf_inf() {
+; CHECK-NEXT:    [[R:%.*]] = call double @erf(double 0x7FF0000000000000)
+; CHECK-NEXT:    ret double [[R]]
+;
+  %r = call double @erf(double 0x7FF0000000000000)
+  ret double %r
+}
+
+define float @erff_inf_memory_none() {
+; CHECK-LABEL: define float @erff_inf_memory_none() {
+; CHECK-NEXT:    [[R:%.*]] = call float @erff(float 0x7FF0000000000000) #[[ATTR0:[0-9]+]]
+; CHECK-NEXT:    ret float [[R]]
+;
+  %r = call float @erff(float 0x7FF0000000000000) readnone
+  ret float %r
+}
+
+define double @erf_inf_memory_none() {
+; CHECK-LABEL: define double @erf_inf_memory_none() {
+; CHECK-NEXT:    [[R:%.*]] = call double @erf(double 0x7FF0000000000000) #[[ATTR0]]
+; CHECK-NEXT:    ret double [[R]]
+;
+  %r = call double @erf(double 0x7FF0000000000000) readnone
+  ret double %r
+}
+
+define float @erff_neg_inf() {
+; CHECK-LABEL: define float @erff_neg_inf() {
+; CHECK-NEXT:    [[R:%.*]] = call float @erff(float 0xFFF0000000000000)
+; CHECK-NEXT:    ret float [[R]]
+;
+  %r = call float @erff(float 0xFFF0000000000000)
+  ret float %r
+}
+
+define double @erf_neg_inf() {
+; CHECK-LABEL: define double @erf_neg_inf() {
+; CHECK-NEXT:    [[R:%.*]] = call double @erf(double 0xFFF0000000000000)
+; CHECK-NEXT:    ret double [[R]]
+;
+  %r = call double @erf(double 0xFFF0000000000000)
+  ret double %r
+}
+
+define float @erff_neg_inf_memory_none() {
+; CHECK-LABEL: define float @erff_neg_inf_memory_none() {
+; CHECK-NEXT:    [[R:%.*]] = call float @erff(float 0xFFF0000000000000) #[[ATTR0]]
+; CHECK-NEXT:    ret float [[R]]
+;
+  %r = call float @erff(float 0xFFF0000000000000) readnone
+  ret float %r
+}
+
+define double @erf_neg_inf_memory_none() {
+; CHECK-LABEL: define double @erf_neg_inf_memory_none() {
+; CHECK-NEXT:    [[R:%.*]] = call double @erf(double 0xFFF0000000000000) #[[ATTR0]]
+; CHECK-NEXT:    ret double [[R]]
+;
+  %r = call double @erf(double 0xFFF0000000000000) readnone
+  ret double %r
+}
+
+define float @erff_nan() {
+; CHECK-LABEL: define float @erff_nan() {
+; CHECK-NEXT:    [[R:%.*]] = call float @erff(float 0x7FF8000000000000)
+; CHECK-NEXT:    ret float [[R]]
+;
+  %r = call float @erff(float 0x7FF8000000000000)
+  ret float %r
+}
+
+define double @erf_nan() {
+; CHECK-LABEL: define double @erf_nan() {
+; CHECK-NEXT:    [[R:%.*]] = call double @erf(double 0x7FF8000000000000)
+; CHECK-NEXT:    ret double [[R]]
+;
+  %r = call double @erf(double 0x7FF8000000000000)
+  ret double %r
+}
+
+define float @erff_nan_memory_none() {
+; CHECK-LABEL: define float @erff_nan_memory_none() {
+; CHECK-NEXT:    [[R:%.*]] = call float @erff(float 0x7FF8000000000000) #[[ATTR0]]
+; CHECK-NEXT:    ret float [[R]]
+;
+  %r = call float @erff(float 0x7FF8000000000000) readnone
+  ret float %r
+}
+
+define double @erf_nan_memory_none() {
+; CHECK-LABEL: define double @erf_nan_memory_none() {
+; CHECK-NEXT:    [[R:%.*]] = call double @erf(double 0x7FF8000000000000) #[[ATTR0]]
+; CHECK-NEXT:    ret double [[R]]
+;
+  %r = call double @erf(double 0x7FF8000000000000) readnone
+  ret double %r
+}
+
+define float @erff_poison() {
+; CHECK-LABEL: define float @erff_poison() {
+; CHECK-NEXT:    [[R:%.*]] = call float @erff(float poison)
+; CHECK-NEXT:    ret float [[R]]
+;
+  %r = call float @erff(float poison)
+  ret float %r
+}
+
+define double @erf_poison() {
+; CHECK-LABEL: define double @erf_poison() {
+; CHECK-NEXT:    [[R:%.*]] = call double @erf(double poison)
+; CHECK-NEXT:    ret double [[R]]
+;
+  %r = call double @erf(double poison)
+  ret double %r
+}
+
----------------
arsenm wrote:

Negative test for a strictfp case that raises an exception, and one that does not 

https://github.com/llvm/llvm-project/pull/113079