[llvm] r327342 - [InstCombine] add test to show fmul transform creates extra fdiv; NFC
Sanjay Patel via llvm-commits
llvm-commits at lists.llvm.org
Mon Mar 12 16:10:08 PDT 2018
Author: spatel
Date: Mon Mar 12 16:10:08 2018
New Revision: 327342
URL: http://llvm.org/viewvc/llvm-project?rev=327342&view=rev
Log:
[InstCombine] add test to show fmul transform creates extra fdiv; NFC
Also, move fmul reassociation tests to the same file as other fmul transforms.
Modified:
llvm/trunk/test/Transforms/InstCombine/fast-math.ll
llvm/trunk/test/Transforms/InstCombine/fmul.ll
Modified: llvm/trunk/test/Transforms/InstCombine/fast-math.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/fast-math.ll?rev=327342&r1=327341&r2=327342&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/fast-math.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/fast-math.ll Mon Mar 12 16:10:08 2018
@@ -273,94 +273,6 @@ define float @fmul_distribute4(float %f1
ret float %t3
}
-; C1/X * C2 => (C1*C2) / X
-define float @fmul2(float %f1) {
-; CHECK-LABEL: @fmul2(
-; CHECK-NEXT: [[TMP1:%.*]] = fdiv fast float 1.200000e+07, [[F1:%.*]]
-; CHECK-NEXT: ret float [[TMP1]]
-;
- %t1 = fdiv float 2.0e+3, %f1
- %t3 = fmul fast float %t1, 6.0e+3
- ret float %t3
-}
-
-; X/C1 * C2 => X * (C2/C1) is disabled if X/C1 has multiple uses
- at fmul2_external = external global float
-define float @fmul2_disable(float %f1) {
-; CHECK-LABEL: @fmul2_disable(
-; CHECK-NEXT: [[DIV:%.*]] = fdiv fast float 1.000000e+00, [[F1:%.*]]
-; CHECK-NEXT: store float [[DIV]], float* @fmul2_external, align 4
-; CHECK-NEXT: [[MUL:%.*]] = fmul fast float [[DIV]], 2.000000e+00
-; CHECK-NEXT: ret float [[MUL]]
-;
- %div = fdiv fast float 1.000000e+00, %f1
- store float %div, float* @fmul2_external
- %mul = fmul fast float %div, 2.000000e+00
- ret float %mul
-}
-
-; X/C1 * C2 => X * (C2/C1) (if C2/C1 is normal Fp)
-define float @fmul3(float %f1, float %f2) {
-; CHECK-LABEL: @fmul3(
-; CHECK-NEXT: [[TMP1:%.*]] = fmul fast float [[F1:%.*]], 3.000000e+00
-; CHECK-NEXT: ret float [[TMP1]]
-;
- %t1 = fdiv float %f1, 2.0e+3
- %t3 = fmul fast float %t1, 6.0e+3
- ret float %t3
-}
-
-define <4 x float> @fmul3_vec(<4 x float> %f1, <4 x float> %f2) {
-; CHECK-LABEL: @fmul3_vec(
-; CHECK-NEXT: [[TMP1:%.*]] = fmul fast <4 x float> [[F1:%.*]], <float 3.000000e+00, float 2.000000e+00, float 1.000000e+00, float 1.000000e+00>
-; CHECK-NEXT: ret <4 x float> [[TMP1]]
-;
- %t1 = fdiv <4 x float> %f1, <float 2.0e+3, float 3.0e+3, float 2.0e+3, float 1.0e+3>
- %t3 = fmul fast <4 x float> %t1, <float 6.0e+3, float 6.0e+3, float 2.0e+3, float 1.0e+3>
- ret <4 x float> %t3
-}
-
-; Make sure fmul with constant expression doesn't assert.
-define <4 x float> @fmul3_vec_constexpr(<4 x float> %f1, <4 x float> %f2) {
-; CHECK-LABEL: @fmul3_vec_constexpr(
-; CHECK-NEXT: [[TMP1:%.*]] = fmul fast <4 x float> [[F1:%.*]], <float 3.000000e+00, float 2.000000e+00, float 1.000000e+00, float 1.000000e+00>
-; CHECK-NEXT: ret <4 x float> [[TMP1]]
-;
- %constExprMul = bitcast i128 trunc (i160 bitcast (<5 x float> <float 6.0e+3, float 6.0e+3, float 2.0e+3, float 1.0e+3, float undef> to i160) to i128) to <4 x float>
- %t1 = fdiv <4 x float> %f1, <float 2.0e+3, float 3.0e+3, float 2.0e+3, float 1.0e+3>
- %t3 = fmul fast <4 x float> %t1, %constExprMul
- ret <4 x float> %t3
-}
-
-; Rule "X/C1 * C2 => X * (C2/C1) is not applicable if C2/C1 is either a special
-; value of a denormal. The 0x3810000000000000 here take value FLT_MIN
-;
-define float @fmul4(float %f1, float %f2) {
-; CHECK-LABEL: @fmul4(
-; CHECK-NEXT: [[T1:%.*]] = fdiv float [[F1:%.*]], 2.000000e+03
-; CHECK-NEXT: [[T3:%.*]] = fmul fast float [[T1]], 0x3810000000000000
-; CHECK-NEXT: ret float [[T3]]
-;
- %t1 = fdiv float %f1, 2.0e+3
- %t3 = fmul fast float %t1, 0x3810000000000000
- ret float %t3
-}
-
-; X / C1 * C2 => X / (C2/C1) if C1/C2 is either a special value of a denormal,
-; and C2/C1 is a normal value.
-; TODO: We don't convert the fast fdiv to fmul because that would be multiplication
-; by a denormal, but we could do better when we know that denormals are not a problem.
-
-define float @fmul5(float %f1, float %f2) {
-; CHECK-LABEL: @fmul5(
-; CHECK-NEXT: [[TMP1:%.*]] = fdiv fast float [[F1:%.*]], 0x47E8000000000000
-; CHECK-NEXT: ret float [[TMP1]]
-;
- %t1 = fdiv float %f1, 3.0e+0
- %t3 = fmul fast float %t1, 0x3810000000000000
- ret float %t3
-}
-
; "(X*Y) * X => (X*X) * Y" is disabled if "X*Y" has multiple uses
define float @fmul7(float %f1, float %f2) {
; CHECK-LABEL: @fmul7(
Modified: llvm/trunk/test/Transforms/InstCombine/fmul.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/fmul.ll?rev=327342&r1=327341&r2=327342&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/fmul.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/fmul.ll Mon Mar 12 16:10:08 2018
@@ -332,3 +332,110 @@ define float @log2half_commute(float %x1
ret float %mul
}
+; C1/X * C2 => (C1*C2) / X
+
+define float @fdiv_constant_numerator_fmul(float %x) {
+; CHECK-LABEL: @fdiv_constant_numerator_fmul(
+; CHECK-NEXT: [[TMP1:%.*]] = fdiv fast float 1.200000e+07, [[X:%.*]]
+; CHECK-NEXT: ret float [[TMP1]]
+;
+ %t1 = fdiv float 2.0e+3, %x
+ %t3 = fmul fast float %t1, 6.0e+3
+ ret float %t3
+}
+
+; C1/X * C2 => (C1*C2) / X is disabled if C1/X has multiple uses
+
+ at fmul2_external = external global float
+
+define float @fdiv_constant_numerator_fmul_extra_use(float %x) {
+; CHECK-LABEL: @fdiv_constant_numerator_fmul_extra_use(
+; CHECK-NEXT: [[DIV:%.*]] = fdiv fast float 1.000000e+00, [[X:%.*]]
+; CHECK-NEXT: store float [[DIV]], float* @fmul2_external, align 4
+; CHECK-NEXT: [[MUL:%.*]] = fmul fast float [[DIV]], 2.000000e+00
+; CHECK-NEXT: ret float [[MUL]]
+;
+ %div = fdiv fast float 1.0, %x
+ store float %div, float* @fmul2_external
+ %mul = fmul fast float %div, 2.0
+ ret float %mul
+}
+
+; X/C1 * C2 => X * (C2/C1) (if C2/C1 is normal FP)
+
+define float @fdiv_constant_denominator_fmul(float %x) {
+; CHECK-LABEL: @fdiv_constant_denominator_fmul(
+; CHECK-NEXT: [[TMP1:%.*]] = fmul fast float [[X:%.*]], 3.000000e+00
+; CHECK-NEXT: ret float [[TMP1]]
+;
+ %t1 = fdiv float %x, 2.0e+3
+ %t3 = fmul fast float %t1, 6.0e+3
+ ret float %t3
+}
+
+define <4 x float> @fdiv_constant_denominator_fmul_vec(<4 x float> %x) {
+; CHECK-LABEL: @fdiv_constant_denominator_fmul_vec(
+; CHECK-NEXT: [[TMP1:%.*]] = fmul fast <4 x float> [[X:%.*]], <float 3.000000e+00, float 2.000000e+00, float 1.000000e+00, float 1.000000e+00>
+; CHECK-NEXT: ret <4 x float> [[TMP1]]
+;
+ %t1 = fdiv <4 x float> %x, <float 2.0e+3, float 3.0e+3, float 2.0e+3, float 1.0e+3>
+ %t3 = fmul fast <4 x float> %t1, <float 6.0e+3, float 6.0e+3, float 2.0e+3, float 1.0e+3>
+ ret <4 x float> %t3
+}
+
+; Make sure fmul with constant expression doesn't assert.
+
+define <4 x float> @fdiv_constant_denominator_fmul_vec_constexpr(<4 x float> %x) {
+; CHECK-LABEL: @fdiv_constant_denominator_fmul_vec_constexpr(
+; CHECK-NEXT: [[TMP1:%.*]] = fmul fast <4 x float> [[X:%.*]], <float 3.000000e+00, float 2.000000e+00, float 1.000000e+00, float 1.000000e+00>
+; CHECK-NEXT: ret <4 x float> [[TMP1]]
+;
+ %constExprMul = bitcast i128 trunc (i160 bitcast (<5 x float> <float 6.0e+3, float 6.0e+3, float 2.0e+3, float 1.0e+3, float undef> to i160) to i128) to <4 x float>
+ %t1 = fdiv <4 x float> %x, <float 2.0e+3, float 3.0e+3, float 2.0e+3, float 1.0e+3>
+ %t3 = fmul fast <4 x float> %t1, %constExprMul
+ ret <4 x float> %t3
+}
+
+; Rule "X/C1 * C2 => X * (C2/C1) is not applicable if C2/C1 is abnormal
+; 0x3810000000000000 == FLT_MIN
+
+define float @fdiv_constant_denominator_fmul_denorm(float %x) {
+; CHECK-LABEL: @fdiv_constant_denominator_fmul_denorm(
+; CHECK-NEXT: [[T1:%.*]] = fdiv float [[X:%.*]], 2.000000e+03
+; CHECK-NEXT: [[T3:%.*]] = fmul fast float [[T1]], 0x3810000000000000
+; CHECK-NEXT: ret float [[T3]]
+;
+ %t1 = fdiv float %x, 2.0e+3
+ %t3 = fmul fast float %t1, 0x3810000000000000
+ ret float %t3
+}
+
+; X / C1 * C2 => X / (C2/C1) if C1/C2 is abnormal, but C2/C1 is a normal value.
+; TODO: We don't convert the fast fdiv to fmul because that would be multiplication
+; by a denormal, but we could do better when we know that denormals are not a problem.
+
+define float @fdiv_constant_denominator_fmul_denorm_try_harder(float %x) {
+; CHECK-LABEL: @fdiv_constant_denominator_fmul_denorm_try_harder(
+; CHECK-NEXT: [[TMP1:%.*]] = fdiv fast float [[X:%.*]], 0x47E8000000000000
+; CHECK-NEXT: ret float [[TMP1]]
+;
+ %t1 = fdiv float %x, 3.0
+ %t3 = fmul fast float %t1, 0x3810000000000000
+ ret float %t3
+}
+
+; FIXME: We have 2 divisions instead of the 1 we started with.
+
+define float @fdiv_constant_denominator_fmul_denorm_try_harder_extra_use(float %x) {
+; CHECK-LABEL: @fdiv_constant_denominator_fmul_denorm_try_harder_extra_use(
+; CHECK-NEXT: [[T1:%.*]] = fdiv float [[X:%.*]], 3.000000e+00
+; CHECK-NEXT: [[TMP1:%.*]] = fdiv fast float [[X]], 0x47E8000000000000
+; CHECK-NEXT: [[R:%.*]] = fadd float [[T1]], [[TMP1]]
+; CHECK-NEXT: ret float [[R]]
+;
+ %t1 = fdiv float %x, 3.0e+0
+ %t3 = fmul fast float %t1, 0x3810000000000000
+ %r = fadd float %t1, %t3
+ ret float %r
+}
+
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