[PowerPC] add tests for FMF propagation; NFC

I'm choosing PPC out of convenience because it does
all of the transforms of interest in these tests by
default. There are multiple FMF problems shown in the 
current checks. D45710 is proposing to fix part of 
that.

llvm-svn: 331471

1 files changed, 355 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/PowerPC/fmf-propagation.ll b/llvm/test/CodeGen/PowerPC/fmf-propagation.ll
new file mode 100644
index 00000000000..21d367a461a
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/fmf-propagation.ll
@@ -0,0 +1,355 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; REQUIRES: asserts
+; RUN: llc < %s -mtriple=powerpc64le -debug-only=isel -o /dev/null 2>&1 | FileCheck %s --check-prefix=FMFDEBUG
+; RUN: llc < %s -mtriple=powerpc64le                                    | FileCheck %s --check-prefix=FMF
+; RUN: llc < %s -mtriple=powerpc64le -enable-unsafe-fp-math             | FileCheck %s --check-prefix=GLOBAL
+
+; Test FP transforms using instruction/node-level fast-math-flags.
+; We're also checking debug output to verify that FMF is propagated to the newly created nodes.
+; The run with the global unsafe param tests the pre-FMF behavior using regular instructions/nodes.
+
+declare float @llvm.fma.f32(float, float, float)
+declare float @llvm.sqrt.f32(float)
+
+; X * Y + Z --> fma(X, Y, Z)
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'fmul_fadd_contract1:'
+; FMFDEBUG:         fmul {{t[0-9]+}}, {{t[0-9]+}}
+; FMFDEBUG:         fadd contract {{t[0-9]+}}, {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'fmul_fadd_contract1:'
+
+define float @fmul_fadd_contract1(float %x, float %y, float %z) {
+; FMF-LABEL: fmul_fadd_contract1:
+; FMF:       # %bb.0:
+; FMF-NEXT:    xsmulsp 0, 1, 2
+; FMF-NEXT:    xsaddsp 1, 0, 3
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: fmul_fadd_contract1:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    xsmaddasp 3, 1, 2
+; GLOBAL-NEXT:    fmr 1, 3
+; GLOBAL-NEXT:    blr
+  %mul = fmul float %x, %y
+  %add = fadd contract float %mul, %z
+  ret float %add
+}
+
+; This shouldn't change anything - the intermediate fmul result is now also flagged.
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'fmul_fadd_contract2:'
+; FMFDEBUG:         fma {{t[0-9]+}}, {{t[0-9]+}}, {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'fmul_fadd_contract2:'
+
+define float @fmul_fadd_contract2(float %x, float %y, float %z) {
+; FMF-LABEL: fmul_fadd_contract2:
+; FMF:       # %bb.0:
+; FMF-NEXT:    xsmaddasp 3, 1, 2
+; FMF-NEXT:    fmr 1, 3
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: fmul_fadd_contract2:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    xsmaddasp 3, 1, 2
+; GLOBAL-NEXT:    fmr 1, 3
+; GLOBAL-NEXT:    blr
+  %mul = fmul contract float %x, %y
+  %add = fadd contract float %mul, %z
+  ret float %add
+}
+
+; Reassociation implies that FMA contraction is allowed.
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'fmul_fadd_reassoc1:'
+; FMFDEBUG:         fmul {{t[0-9]+}}, {{t[0-9]+}}
+; FMFDEBUG:         fadd {{t[0-9]+}}, {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'fmul_fadd_reassoc1:'
+
+define float @fmul_fadd_reassoc1(float %x, float %y, float %z) {
+; FMF-LABEL: fmul_fadd_reassoc1:
+; FMF:       # %bb.0:
+; FMF-NEXT:    xsmulsp 0, 1, 2
+; FMF-NEXT:    xsaddsp 1, 0, 3
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: fmul_fadd_reassoc1:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    xsmaddasp 3, 1, 2
+; GLOBAL-NEXT:    fmr 1, 3
+; GLOBAL-NEXT:    blr
+  %mul = fmul float %x, %y
+  %add = fadd reassoc float %mul, %z
+  ret float %add
+}
+
+; This shouldn't change anything - the intermediate fmul result is now also flagged.
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'fmul_fadd_reassoc2:'
+; FMFDEBUG:         fmul {{t[0-9]+}}, {{t[0-9]+}}
+; FMFDEBUG:         fadd {{t[0-9]+}}, {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'fmul_fadd_reassoc2:'
+
+define float @fmul_fadd_reassoc2(float %x, float %y, float %z) {
+; FMF-LABEL: fmul_fadd_reassoc2:
+; FMF:       # %bb.0:
+; FMF-NEXT:    xsmulsp 0, 1, 2
+; FMF-NEXT:    xsaddsp 1, 0, 3
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: fmul_fadd_reassoc2:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    xsmaddasp 3, 1, 2
+; GLOBAL-NEXT:    fmr 1, 3
+; GLOBAL-NEXT:    blr
+  %mul = fmul reassoc float %x, %y
+  %add = fadd reassoc float %mul, %z
+  ret float %add
+}
+
+; The fadd is now fully 'fast'. This implies that contraction is allowed.
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'fmul_fadd_fast1:'
+; FMFDEBUG:         fma {{t[0-9]+}}, {{t[0-9]+}}, {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'fmul_fadd_fast1:'
+
+define float @fmul_fadd_fast1(float %x, float %y, float %z) {
+; FMF-LABEL: fmul_fadd_fast1:
+; FMF:       # %bb.0:
+; FMF-NEXT:    xsmaddasp 3, 1, 2
+; FMF-NEXT:    fmr 1, 3
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: fmul_fadd_fast1:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    xsmaddasp 3, 1, 2
+; GLOBAL-NEXT:    fmr 1, 3
+; GLOBAL-NEXT:    blr
+  %mul = fmul fast float %x, %y
+  %add = fadd fast float %mul, %z
+  ret float %add
+}
+
+; This shouldn't change anything - the intermediate fmul result is now also flagged.
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'fmul_fadd_fast2:'
+; FMFDEBUG:         fma {{t[0-9]+}}, {{t[0-9]+}}, {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'fmul_fadd_fast2:'
+
+define float @fmul_fadd_fast2(float %x, float %y, float %z) {
+; FMF-LABEL: fmul_fadd_fast2:
+; FMF:       # %bb.0:
+; FMF-NEXT:    xsmaddasp 3, 1, 2
+; FMF-NEXT:    fmr 1, 3
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: fmul_fadd_fast2:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    xsmaddasp 3, 1, 2
+; GLOBAL-NEXT:    fmr 1, 3
+; GLOBAL-NEXT:    blr
+  %mul = fmul fast float %x, %y
+  %add = fadd fast float %mul, %z
+  ret float %add
+}
+
+; fma(X, 7.0, X * 42.0) --> X * 49.0
+; This is the minimum FMF needed for this transform - the FMA allows reassociation.
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'fmul_fma_reassoc1:'
+; FMFDEBUG:         fma {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'fmul_fma_reassoc1:'
+
+define float @fmul_fma_reassoc1(float %x) {
+; FMF-LABEL: fmul_fma_reassoc1:
+; FMF:       # %bb.0:
+; FMF-NEXT:    addis 3, 2, .LCPI6_0@toc@ha
+; FMF-NEXT:    addi 3, 3, .LCPI6_0@toc@l
+; FMF-NEXT:    lfsx 0, 0, 3
+; FMF-NEXT:    addis 3, 2, .LCPI6_1@toc@ha
+; FMF-NEXT:    addi 3, 3, .LCPI6_1@toc@l
+; FMF-NEXT:    lfsx 2, 0, 3
+; FMF-NEXT:    xsmulsp 0, 1, 0
+; FMF-NEXT:    xsmaddasp 0, 1, 2
+; FMF-NEXT:    fmr 1, 0
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: fmul_fma_reassoc1:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    addis 3, 2, .LCPI6_0@toc@ha
+; GLOBAL-NEXT:    addi 3, 3, .LCPI6_0@toc@l
+; GLOBAL-NEXT:    lfsx 0, 0, 3
+; GLOBAL-NEXT:    xsmulsp 1, 1, 0
+; GLOBAL-NEXT:    blr
+  %mul = fmul float %x, 42.0
+  %fma = call reassoc float @llvm.fma.f32(float %x, float 7.0, float %mul)
+  ret float %fma
+}
+
+; This shouldn't change anything - the intermediate fmul result is now also flagged.
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'fmul_fma_reassoc2:'
+; FMFDEBUG:         fma {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'fmul_fma_reassoc2:'
+
+define float @fmul_fma_reassoc2(float %x) {
+; FMF-LABEL: fmul_fma_reassoc2:
+; FMF:       # %bb.0:
+; FMF-NEXT:    addis 3, 2, .LCPI7_0@toc@ha
+; FMF-NEXT:    addi 3, 3, .LCPI7_0@toc@l
+; FMF-NEXT:    lfsx 0, 0, 3
+; FMF-NEXT:    addis 3, 2, .LCPI7_1@toc@ha
+; FMF-NEXT:    addi 3, 3, .LCPI7_1@toc@l
+; FMF-NEXT:    lfsx 2, 0, 3
+; FMF-NEXT:    xsmulsp 0, 1, 0
+; FMF-NEXT:    xsmaddasp 0, 1, 2
+; FMF-NEXT:    fmr 1, 0
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: fmul_fma_reassoc2:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    addis 3, 2, .LCPI7_0@toc@ha
+; GLOBAL-NEXT:    addi 3, 3, .LCPI7_0@toc@l
+; GLOBAL-NEXT:    lfsx 0, 0, 3
+; GLOBAL-NEXT:    xsmulsp 1, 1, 0
+; GLOBAL-NEXT:    blr
+  %mul = fmul reassoc float %x, 42.0
+  %fma = call reassoc float @llvm.fma.f32(float %x, float 7.0, float %mul)
+  ret float %fma
+}
+
+; The FMA is now fully 'fast'. This implies that reassociation is allowed.
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'fmul_fma_fast1:'
+; FMFDEBUG:         fma {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'fmul_fma_fast1:'
+
+define float @fmul_fma_fast1(float %x) {
+; FMF-LABEL: fmul_fma_fast1:
+; FMF:       # %bb.0:
+; FMF-NEXT:    addis 3, 2, .LCPI8_0@toc@ha
+; FMF-NEXT:    addi 3, 3, .LCPI8_0@toc@l
+; FMF-NEXT:    lfsx 0, 0, 3
+; FMF-NEXT:    addis 3, 2, .LCPI8_1@toc@ha
+; FMF-NEXT:    addi 3, 3, .LCPI8_1@toc@l
+; FMF-NEXT:    lfsx 2, 0, 3
+; FMF-NEXT:    xsmulsp 0, 1, 0
+; FMF-NEXT:    xsmaddasp 0, 1, 2
+; FMF-NEXT:    fmr 1, 0
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: fmul_fma_fast1:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    addis 3, 2, .LCPI8_0@toc@ha
+; GLOBAL-NEXT:    addi 3, 3, .LCPI8_0@toc@l
+; GLOBAL-NEXT:    lfsx 0, 0, 3
+; GLOBAL-NEXT:    xsmulsp 1, 1, 0
+; GLOBAL-NEXT:    blr
+  %mul = fmul float %x, 42.0
+  %fma = call fast float @llvm.fma.f32(float %x, float 7.0, float %mul)
+  ret float %fma
+}
+
+; This shouldn't change anything - the intermediate fmul result is now also flagged.
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'fmul_fma_fast2:'
+; FMFDEBUG:         fma {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'fmul_fma_fast2:'
+
+define float @fmul_fma_fast2(float %x) {
+; FMF-LABEL: fmul_fma_fast2:
+; FMF:       # %bb.0:
+; FMF-NEXT:    addis 3, 2, .LCPI9_0@toc@ha
+; FMF-NEXT:    addi 3, 3, .LCPI9_0@toc@l
+; FMF-NEXT:    lfsx 0, 0, 3
+; FMF-NEXT:    addis 3, 2, .LCPI9_1@toc@ha
+; FMF-NEXT:    addi 3, 3, .LCPI9_1@toc@l
+; FMF-NEXT:    lfsx 2, 0, 3
+; FMF-NEXT:    xsmulsp 0, 1, 0
+; FMF-NEXT:    xsmaddasp 0, 1, 2
+; FMF-NEXT:    fmr 1, 0
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: fmul_fma_fast2:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    addis 3, 2, .LCPI9_0@toc@ha
+; GLOBAL-NEXT:    addi 3, 3, .LCPI9_0@toc@l
+; GLOBAL-NEXT:    lfsx 0, 0, 3
+; GLOBAL-NEXT:    xsmulsp 1, 1, 0
+; GLOBAL-NEXT:    blr
+  %mul = fmul fast float %x, 42.0
+  %fma = call fast float @llvm.fma.f32(float %x, float 7.0, float %mul)
+  ret float %fma
+}
+
+; Reduced precision for sqrt is allowed - should use estimate and NR iterations.
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'sqrt_afn:'
+; FMFDEBUG:         fsqrt {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'sqrt_afn:'
+
+define float @sqrt_afn(float %x) {
+; FMF-LABEL: sqrt_afn:
+; FMF:       # %bb.0:
+; FMF-NEXT:    xssqrtsp 1, 1
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: sqrt_afn:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    xxlxor 0, 0, 0
+; GLOBAL-NEXT:    fcmpu 0, 1, 0
+; GLOBAL-NEXT:    beq 0, .LBB10_2
+; GLOBAL-NEXT:  # %bb.1:
+; GLOBAL-NEXT:    xsrsqrtesp 2, 1
+; GLOBAL-NEXT:    addis 3, 2, .LCPI10_0@toc@ha
+; GLOBAL-NEXT:    fneg 0, 1
+; GLOBAL-NEXT:    fmr 4, 1
+; GLOBAL-NEXT:    addi 3, 3, .LCPI10_0@toc@l
+; GLOBAL-NEXT:    lfsx 3, 0, 3
+; GLOBAL-NEXT:    xsmaddasp 4, 0, 3
+; GLOBAL-NEXT:    xsmulsp 0, 2, 2
+; GLOBAL-NEXT:    xsmaddasp 3, 4, 0
+; GLOBAL-NEXT:    xsmulsp 0, 2, 3
+; GLOBAL-NEXT:    xsmulsp 0, 0, 1
+; GLOBAL-NEXT:  .LBB10_2:
+; GLOBAL-NEXT:    fmr 1, 0
+; GLOBAL-NEXT:    blr
+  %rt = call afn float @llvm.sqrt.f32(float %x)
+  ret float %rt
+}
+
+; The call is now fully 'fast'. This implies that approximation is allowed.
+
+; FMFDEBUG-LABEL: Optimized lowered selection DAG: %bb.0 'sqrt_fast:'
+; FMFDEBUG:         fsqrt {{t[0-9]+}}
+; FMFDEBUG:       Type-legalized selection DAG: %bb.0 'sqrt_fast:'
+
+define float @sqrt_fast(float %x) {
+; FMF-LABEL: sqrt_fast:
+; FMF:       # %bb.0:
+; FMF-NEXT:    xssqrtsp 1, 1
+; FMF-NEXT:    blr
+;
+; GLOBAL-LABEL: sqrt_fast:
+; GLOBAL:       # %bb.0:
+; GLOBAL-NEXT:    xxlxor 0, 0, 0
+; GLOBAL-NEXT:    fcmpu 0, 1, 0
+; GLOBAL-NEXT:    beq 0, .LBB11_2
+; GLOBAL-NEXT:  # %bb.1:
+; GLOBAL-NEXT:    xsrsqrtesp 2, 1
+; GLOBAL-NEXT:    addis 3, 2, .LCPI11_0@toc@ha
+; GLOBAL-NEXT:    fneg 0, 1
+; GLOBAL-NEXT:    fmr 4, 1
+; GLOBAL-NEXT:    addi 3, 3, .LCPI11_0@toc@l
+; GLOBAL-NEXT:    lfsx 3, 0, 3
+; GLOBAL-NEXT:    xsmaddasp 4, 0, 3
+; GLOBAL-NEXT:    xsmulsp 0, 2, 2
+; GLOBAL-NEXT:    xsmaddasp 3, 4, 0
+; GLOBAL-NEXT:    xsmulsp 0, 2, 3
+; GLOBAL-NEXT:    xsmulsp 0, 0, 1
+; GLOBAL-NEXT:  .LBB11_2:
+; GLOBAL-NEXT:    fmr 1, 0
+; GLOBAL-NEXT:    blr
+  %rt = call fast float @llvm.sqrt.f32(float %x)
+  ret float %rt
+}
+