Combine fmul vector FP constants when unsafe math is allowed.
This is an extension of the change made with r215820:
http://llvm.org/viewvc/llvm-project?view=revision&revision=215820
That patch allowed combining of splatted vector FP constants that are multiplied.
This patch allows combining non-uniform vector FP constants too by relaxing the
check on the type of vector. Also, canonicalize a vector fmul in the
same way that we already do for scalars - if only one operand of the fmul is a
constant, make it operand 1. Otherwise, we miss potential folds.
This fold is also done by -instcombine, but it's possible that extra
fmuls may have been generated during lowering.
Differential Revision: http://reviews.llvm.org/D5254
llvm-svn: 217599
diff --git a/llvm/test/CodeGen/X86/fmul-combines.ll b/llvm/test/CodeGen/X86/fmul-combines.ll
index a012235..be04107 100644
--- a/llvm/test/CodeGen/X86/fmul-combines.ll
+++ b/llvm/test/CodeGen/X86/fmul-combines.ll
@@ -55,6 +55,54 @@
ret <4 x float> %z
}
+; We should be able to pre-multiply the two constant vectors.
+; CHECK: ## float 5.000000e+00
+; CHECK: ## float 1.200000e+01
+; CHECK: ## float 2.100000e+01
+; CHECK: ## float 3.200000e+01
+; CHECK-LABEL: fmul_v4f32_two_consts_no_splat:
+; CHECK: mulps
+; CHECK-NOT: mulps
+; CHECK-NEXT: ret
+define <4 x float> @fmul_v4f32_two_consts_no_splat(<4 x float> %x) #0 {
+ %y = fmul <4 x float> %x, <float 1.0, float 2.0, float 3.0, float 4.0>
+ %z = fmul <4 x float> %y, <float 5.0, float 6.0, float 7.0, float 8.0>
+ ret <4 x float> %z
+}
+
+; Same as above, but reverse operands to make sure non-canonical form is also handled.
+; CHECK: ## float 5.000000e+00
+; CHECK: ## float 1.200000e+01
+; CHECK: ## float 2.100000e+01
+; CHECK: ## float 3.200000e+01
+; CHECK-LABEL: fmul_v4f32_two_consts_no_splat_non_canonical:
+; CHECK: mulps
+; CHECK-NOT: mulps
+; CHECK-NEXT: ret
+define <4 x float> @fmul_v4f32_two_consts_no_splat_non_canonical(<4 x float> %x) #0 {
+ %y = fmul <4 x float> <float 1.0, float 2.0, float 3.0, float 4.0>, %x
+ %z = fmul <4 x float> <float 5.0, float 6.0, float 7.0, float 8.0>, %y
+ ret <4 x float> %z
+}
+
+; More than one use of a constant multiply should not inhibit the optimization.
+; Instead of a chain of 2 dependent mults, this test will have 2 independent mults.
+; CHECK: ## float 5.000000e+00
+; CHECK: ## float 1.200000e+01
+; CHECK: ## float 2.100000e+01
+; CHECK: ## float 3.200000e+01
+; CHECK-LABEL: fmul_v4f32_two_consts_no_splat_multiple_use:
+; CHECK: mulps
+; CHECK: mulps
+; CHECK: addps
+; CHECK: ret
+define <4 x float> @fmul_v4f32_two_consts_no_splat_multiple_use(<4 x float> %x) #0 {
+ %y = fmul <4 x float> %x, <float 1.0, float 2.0, float 3.0, float 4.0>
+ %z = fmul <4 x float> %y, <float 5.0, float 6.0, float 7.0, float 8.0>
+ %a = fadd <4 x float> %y, %z
+ ret <4 x float> %a
+}
+
; CHECK-LABEL: fmul_c2_c4_f32:
; CHECK-NOT: addss
; CHECK: mulss