[IR] allow fast-math-flags on select of FP values

This is a minimal start to correcting a problem most directly discussed in PR38086:
https://bugs.llvm.org/show_bug.cgi?id=38086

We have been hacking around a limitation for FP select patterns by using the
fast-math-flags on the condition of the select rather than the select itself.
This patch just allows FMF to appear with the 'select' opcode. No changes are
needed to "FPMathOperator" because it already includes select-of-FP because
that definition is based on the (return) value type.

Once we have this ability, we can start correcting and adding IR transforms
to use the FMF on a 'select' instruction. The instcombine and vectorizer test
diffs only show that the IRBuilder change is behaving as expected by applying
an FMF guard value to 'select'.

For reference:
rL241901 - allowed FMF with fcmp
rL255555 - allowed FMF with FP calls

Differential Revision: https://reviews.llvm.org/D61917

llvm-svn: 361401

2 files changed, 19 insertions, 19 deletions

diff --git a/llvm/test/Transforms/LoopVectorize/float-minmax-instruction-flag.ll b/llvm/test/Transforms/LoopVectorize/float-minmax-instruction-flag.ll
index c65e0dbf9e5..8b86a71b85e 100644
--- a/llvm/test/Transforms/LoopVectorize/float-minmax-instruction-flag.ll
+++ b/llvm/test/Transforms/LoopVectorize/float-minmax-instruction-flag.ll
@@ -74,10 +74,10 @@ define float @minloopattr(float* nocapture readonly %arg) #0 {
 ; CHECK:       middle.block:
 ; CHECK-NEXT:    [[RDX_SHUF:%.*]] = shufflevector <4 x float> [[TMP6]], <4 x float> undef, <4 x i32> <i32 2, i32 3, i32 undef, i32 undef>
 ; CHECK-NEXT:    [[RDX_MINMAX_CMP:%.*]] = fcmp fast olt <4 x float> [[TMP6]], [[RDX_SHUF]]
-; CHECK-NEXT:    [[RDX_MINMAX_SELECT:%.*]] = select <4 x i1> [[RDX_MINMAX_CMP]], <4 x float> [[TMP6]], <4 x float> [[RDX_SHUF]]
+; CHECK-NEXT:    [[RDX_MINMAX_SELECT:%.*]] = select fast <4 x i1> [[RDX_MINMAX_CMP]], <4 x float> [[TMP6]], <4 x float> [[RDX_SHUF]]
 ; CHECK-NEXT:    [[RDX_SHUF1:%.*]] = shufflevector <4 x float> [[RDX_MINMAX_SELECT]], <4 x float> undef, <4 x i32> <i32 1, i32 undef, i32 undef, i32 undef>
 ; CHECK-NEXT:    [[RDX_MINMAX_CMP2:%.*]] = fcmp fast olt <4 x float> [[RDX_MINMAX_SELECT]], [[RDX_SHUF1]]
-; CHECK-NEXT:    [[RDX_MINMAX_SELECT3:%.*]] = select <4 x i1> [[RDX_MINMAX_CMP2]], <4 x float> [[RDX_MINMAX_SELECT]], <4 x float> [[RDX_SHUF1]]
+; CHECK-NEXT:    [[RDX_MINMAX_SELECT3:%.*]] = select fast <4 x i1> [[RDX_MINMAX_CMP2]], <4 x float> [[RDX_MINMAX_SELECT]], <4 x float> [[RDX_SHUF1]]
 ; CHECK-NEXT:    [[TMP8:%.*]] = extractelement <4 x float> [[RDX_MINMAX_SELECT3]], i32 0
 ; CHECK-NEXT:    [[CMP_N:%.*]] = icmp eq i64 65536, 65536
 ; CHECK-NEXT:    br i1 [[CMP_N]], label [[OUT:%.*]], label [[SCALAR_PH]]
diff --git a/llvm/test/Transforms/LoopVectorize/minmax_reduction.ll b/llvm/test/Transforms/LoopVectorize/minmax_reduction.ll
index 188700d66d8..fc2f8dcec2f 100644
--- a/llvm/test/Transforms/LoopVectorize/minmax_reduction.ll
+++ b/llvm/test/Transforms/LoopVectorize/minmax_reduction.ll
@@ -416,7 +416,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @max_red_float(float %max) #0 {
 entry:
@@ -442,7 +442,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @max_red_float_ge(float %max) #0 {
 entry:
@@ -468,7 +468,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @inverted_max_red_float(float %max) #0 {
 entry:
@@ -494,7 +494,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @inverted_max_red_float_le(float %max) #0 {
 entry:
@@ -520,7 +520,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @unordered_max_red_float(float %max) #0 {
 entry:
@@ -546,7 +546,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @unordered_max_red_float_ge(float %max) #0 {
 entry:
@@ -572,7 +572,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @inverted_unordered_max_red_float(float %max) #0 {
 entry:
@@ -598,7 +598,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @inverted_unordered_max_red_float_le(float %max) #0 {
 entry:
@@ -627,7 +627,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @min_red_float(float %min) #0 {
 entry:
@@ -653,7 +653,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @min_red_float_le(float %min) #0 {
 entry:
@@ -679,7 +679,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @inverted_min_red_float(float %min) #0 {
 entry:
@@ -705,7 +705,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @inverted_min_red_float_ge(float %min) #0 {
 entry:
@@ -731,7 +731,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @unordered_min_red_float(float %min) #0 {
 entry:
@@ -757,7 +757,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @unordered_min_red_float_le(float %min) #0 {
 entry:
@@ -783,7 +783,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @inverted_unordered_min_red_float(float %min) #0 {
 entry:
@@ -809,7 +809,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define float @inverted_unordered_min_red_float_ge(float %min) #0 {
 entry:
@@ -836,7 +836,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp fast olt <2 x double>
-; CHECK: select <2 x i1>
+; CHECK: select fast <2 x i1>
 
 define double @min_red_double(double %min) #0 {
 entry: