[llvm] [Transforms] Add more cos combinations to SimplifyLibCalls and InstCombine (PR #79699)

[Matt Arsenault via llvm-commits]

================
@@ -100,6 +108,71 @@ define float @cosf_unary_negated_arg_FMF(float %x) {
   ret float %r
 }
 
+; cos(fabs(x)) -> cos(x)
+
+define double @cos_unary_fabs_arg(double %x) {
+; ANY-LABEL: @cos_unary_fabs_arg(
+; ANY-NEXT:    [[COS:%.*]] = call double @cos(double [[X:%.*]])
+; ANY-NEXT:    ret double [[COS]]
+;
+  %fabs = tail call double @llvm.fabs.f64(double %x)
+  %r = call double @cos(double %fabs)
+  ret double %r
+}
+
+define float @cosf_unary_fabs_arg(float %x) {
+; ANY-LABEL: @cosf_unary_fabs_arg(
+; ANY-NEXT:    [[COS:%.*]] = call float @cosf(float [[X:%.*]])
+; ANY-NEXT:    ret float [[COS]]
+;
+  %fabs = tail call float @llvm.fabs.f32(float %x)
+  %r = call float @cosf(float %fabs)
+  ret float %r
+}
+
+define float @cosf_unary_fabs_arg_FMF(float %x) {
+; ANY-LABEL: @cosf_unary_fabs_arg_FMF(
+; ANY-NEXT:    [[COS:%.*]] = call reassoc nnan float @cosf(float [[X:%.*]])
+; ANY-NEXT:    ret float [[COS]]
+;
+  %fabs = tail call float @llvm.fabs.f32(float %x)
+  %r = call nnan reassoc float @cosf(float %fabs)
+  ret float %r
+}
+
+; cos(copysign(x, y)) -> cos(x)
+
+define double @cos_copysign_arg(double %x, double %y) {
+; ANY-LABEL: @cos_copysign_arg(
+; ANY-NEXT:    [[COS:%.*]] = call double @cos(double [[X:%.*]])
+; ANY-NEXT:    ret double [[COS]]
+;
+  %copysign = tail call double @llvm.copysign(double %x, double %y)
+  %r = call double @cos(double %copysign)
+  ret double %r
+}
+
+
+define float @cosf_unary_copysign_arg(float %x) {
+; ANY-LABEL: @cosf_unary_copysign_arg(
+; ANY-NEXT:    [[COS:%.*]] = call float @cosf(float [[X:%.*]])
+; ANY-NEXT:    ret float [[COS]]
+;
+  %copysign = tail call float @llvm.copysign.f32(float %x, float 1.0)
+  %r = call float @cosf(float %copysign)
+  ret float %r
+}
+
+define float @cosf_copysign_arg_FMF(float %x, float %y) {
+; ANY-LABEL: @cosf_copysign_arg_FMF(
+; ANY-NEXT:    [[COS:%.*]] = call reassoc nnan float @cosf(float [[X:%.*]])
+; ANY-NEXT:    ret float [[COS]]
+;
+  %copysign = tail call float @llvm.copysign.f32(float %x, float %y)
+  %r = call nnan reassoc float @cosf(float %copysign)
+  ret float %r
+}
+
----------------
arsenm wrote:

test a vector intrinsic case?

https://github.com/llvm/llvm-project/pull/79699