[llvm] [SimplifyLibCalls] fdim constant fold (PR #109235)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,36 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt %s -passes=instcombine -S -mtriple=i386-pc-windows-msvc | FileCheck %s --check-prefixes=MSVC19
+
+define double @fdim_double() {
+; MSVC19-LABEL: define double @fdim_double() {
+; MSVC19-NEXT:    ret double 2.500000e+00
+;
+  %dim = call double @fdim(double 10.5, double 8.0)
+  ret double %dim
+}
+
+;fdimf is not supported by windows
+define float @fdim_float() {
+; MSVC19-LABEL: define float @fdim_float() {
+; MSVC19-NEXT:    [[DIM:%.*]] = call float @fdimf(float 1.500000e+00, float 8.000000e+00)
+; MSVC19-NEXT:    ret float [[DIM]]
+;
+  %dim = call float @fdimf(float 1.500000e+00, float 8.0)
+  ret float %dim
+}
+
+;fdiml is not supported by windows
+define fp128 @fdim_long() {
+; MSVC19-LABEL: define fp128 @fdim_long() {
+; MSVC19-NEXT:    [[DIM:%.*]] = call fp128 @fdiml(fp128 0xL00000000000000000000000000000000, fp128 0xL00000000000000000000000000000000)
+; MSVC19-NEXT:    ret fp128 [[DIM]]
+;
+  %dim = call fp128 @fdiml(fp128  0xL00000000000000000000000000000000 , fp128 0xL00000000000000000000000000000000)
+  ret fp128 %dim
+}
+
+declare double @fdim(double, double) #0
+declare float @fdimf(float, float) #0
+declare fp128 @fdiml(fp128, fp128) #0
+
+attributes #0 = { memory(none)}
----------------
arsenm wrote:

```suggestion
attributes #0 = { memory(none) }
```

https://github.com/llvm/llvm-project/pull/109235