cmd/compile: ensure constant folding of pointer arithmetic remains a …

…pointer For c + nil, we want the result to still be of pointer type. Fixes ppc64le build failure with CL 468455, in issue33724.go. The problem in that test is that it requires a nil check to be scheduled before the corresponding load. This normally happens fine because we prioritize nil checks. If we have nilcheck(p) and load(p), once p is scheduled the nil check will always go before the load. The issue we saw in 33724 is that when p is a nil pointer, we ended up with two different p's, an int64(0) as the argument to the nil check and an (*Outer)(0) as the argument to the load. Those two zeroes don't get CSEd, so if the (*Outer)(0) happens to get scheduled first, the load can end up before the nilcheck. Fix this by always having constant arithmetic preserve the pointerness of the value, so that both zeroes are of type *Outer and get CSEd. Update golang#58482 Update golang#33724 Change-Id: Ib9b8c0446f1690b574e0f3c0afb9934efbaf3513 Reviewed-on: https://go-review.googlesource.com/c/go/+/468615 Reviewed-by: Keith Randall <[email protected]> Run-TryBot: Keith Randall <[email protected]> Reviewed-by: David Chase <[email protected]> TryBot-Bypass: Keith Randall <[email protected]>
futurist · Feb 17, 2023 · 21f4340 · 21f4340
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commit 21f4340
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Showing 22 changed files with 65 additions and 34 deletions.
diff --git a/src/cmd/compile/internal/ssa/_gen/386.rules b/src/cmd/compile/internal/ssa/_gen/386.rules
@@ -394,7 +394,7 @@
 (NE (TESTB (SETNEF cmp) (SETNEF cmp)) yes no) => (NEF  cmp yes no)
 
 // fold constants into instructions
-(ADDL x (MOVLconst [c])) => (ADDLconst [c] x)
+(ADDL x (MOVLconst <t> [c])) && !t.IsPtr() => (ADDLconst [c] x)
 (ADDLcarry x (MOVLconst [c])) => (ADDLconstcarry [c] x)
 (ADCL x (MOVLconst [c]) f) => (ADCLconst [c] x f)
 

diff --git a/src/cmd/compile/internal/ssa/_gen/AMD64.rules b/src/cmd/compile/internal/ssa/_gen/AMD64.rules
@@ -746,7 +746,7 @@
 // (SETEQF x) => (ANDQ (SETEQ <typ.Int8> x) (SETORD <typ.Int8> x))
 
 // fold constants into instructions
-(ADDQ x (MOVQconst [c])) && is32Bit(c) => (ADDQconst [int32(c)] x)
+(ADDQ x (MOVQconst <t> [c])) && is32Bit(c) && !t.IsPtr() => (ADDQconst [int32(c)] x)
 (ADDQ x (MOVLconst [c])) => (ADDQconst [c] x)
 (ADDL x (MOVLconst [c])) => (ADDLconst [c] x)
 

diff --git a/src/cmd/compile/internal/ssa/_gen/ARM.rules b/src/cmd/compile/internal/ssa/_gen/ARM.rules
@@ -481,7 +481,7 @@
 (MOVHloadidx ptr idx (MOVHstoreidx ptr2 idx x _)) && isSamePtr(ptr, ptr2) => (MOVHreg x)
 
 // fold constant into arithmetic ops
-(ADD x (MOVWconst [c])) => (ADDconst [c] x)
+(ADD x (MOVWconst <t> [c])) && !t.IsPtr() => (ADDconst [c] x)
 (SUB (MOVWconst [c]) x) => (RSBconst [c] x)
 (SUB x (MOVWconst [c])) => (SUBconst [c] x)
 (RSB (MOVWconst [c]) x) => (SUBconst [c] x)

diff --git a/src/cmd/compile/internal/ssa/_gen/ARM64.rules b/src/cmd/compile/internal/ssa/_gen/ARM64.rules
@@ -1241,7 +1241,7 @@
 (MOVDnop (MOVDconst [c])) => (MOVDconst [c])
 
 // fold constant into arithmetic ops
-(ADD x (MOVDconst [c])) => (ADDconst [c] x)
+(ADD x (MOVDconst <t> [c])) && !t.IsPtr() => (ADDconst [c] x)
 (SUB x (MOVDconst [c])) => (SUBconst [c] x)
 (AND x (MOVDconst [c])) => (ANDconst [c] x)
 (OR  x (MOVDconst [c])) => (ORconst  [c] x)

diff --git a/src/cmd/compile/internal/ssa/_gen/LOONG64.rules b/src/cmd/compile/internal/ssa/_gen/LOONG64.rules
@@ -571,7 +571,7 @@
 (MOVVreg x) && x.Uses == 1 => (MOVVnop x)
 
 // fold constant into arithmetic ops
-(ADDV x (MOVVconst [c])) && is32Bit(c) => (ADDVconst [c] x)
+(ADDV x (MOVVconst <t> [c])) && is32Bit(c) && !t.IsPtr() => (ADDVconst [c] x)
 (SUBV x (MOVVconst [c])) && is32Bit(c) => (SUBVconst [c] x)
 (AND x (MOVVconst [c])) && is32Bit(c) => (ANDconst [c] x)
 (OR  x (MOVVconst [c])) && is32Bit(c) => (ORconst  [c] x)

diff --git a/src/cmd/compile/internal/ssa/_gen/MIPS.rules b/src/cmd/compile/internal/ssa/_gen/MIPS.rules
@@ -567,7 +567,7 @@
 (MOVWnop (MOVWconst [c])) => (MOVWconst [c])
 
 // fold constant into arithmetic ops
-(ADD x (MOVWconst [c])) => (ADDconst [c] x)
+(ADD x (MOVWconst <t> [c])) && !t.IsPtr() => (ADDconst [c] x)
 (SUB x (MOVWconst [c])) => (SUBconst [c] x)
 (AND x (MOVWconst [c])) => (ANDconst [c] x)
 (OR  x (MOVWconst [c])) => (ORconst  [c] x)

diff --git a/src/cmd/compile/internal/ssa/_gen/MIPS64.rules b/src/cmd/compile/internal/ssa/_gen/MIPS64.rules
@@ -567,7 +567,7 @@
 (MOVVnop (MOVVconst [c])) => (MOVVconst [c])
 
 // fold constant into arithmetic ops
-(ADDV x (MOVVconst [c])) && is32Bit(c) => (ADDVconst [c] x)
+(ADDV x (MOVVconst <t> [c])) && is32Bit(c) && !t.IsPtr() => (ADDVconst [c] x)
 (SUBV x (MOVVconst [c])) && is32Bit(c) => (SUBVconst [c] x)
 (AND x (MOVVconst [c])) && is32Bit(c) => (ANDconst [c] x)
 (OR  x (MOVVconst [c])) && is32Bit(c) => (ORconst  [c] x)

diff --git a/src/cmd/compile/internal/ssa/_gen/PPC64.rules b/src/cmd/compile/internal/ssa/_gen/PPC64.rules
@@ -670,7 +670,7 @@
 
 // Arithmetic constant ops
 
-(ADD x (MOVDconst [c])) && is32Bit(c) => (ADDconst [c] x)
+(ADD x (MOVDconst <t> [c])) && is32Bit(c) && !t.IsPtr() => (ADDconst [c] x)
 (ADDconst [c] (ADDconst [d] x)) && is32Bit(c+d) => (ADDconst [c+d] x)
 (ADDconst [0] x) => x
 (SUB x (MOVDconst [c])) && is32Bit(-c) => (ADDconst [-c] x)

diff --git a/src/cmd/compile/internal/ssa/_gen/RISCV64.rules b/src/cmd/compile/internal/ssa/_gen/RISCV64.rules
@@ -757,7 +757,7 @@
 (MOVDnop (MOVDconst [c])) => (MOVDconst [c])
 
 // Fold constant into immediate instructions where possible.
-(ADD (MOVDconst [val]) x) && is32Bit(val) => (ADDI [val] x)
+(ADD (MOVDconst <t> [val]) x) && is32Bit(val) && !t.IsPtr() => (ADDI [val] x)
 (AND (MOVDconst [val]) x) && is32Bit(val) => (ANDI [val] x)
 (OR  (MOVDconst [val]) x) && is32Bit(val) => (ORI  [val] x)
 (XOR (MOVDconst [val]) x) && is32Bit(val) => (XORI [val] x)

diff --git a/src/cmd/compile/internal/ssa/_gen/S390X.rules b/src/cmd/compile/internal/ssa/_gen/S390X.rules
@@ -632,7 +632,7 @@
 (BRC {c} (CMPWUconst x [y]) yes no) && y == int32( int8(y)) && (c == s390x.Equal || c == s390x.LessOrGreater) => (CIJ   {c} x [ int8(y)] yes no)
 
 // Fold constants into instructions.
-(ADD x (MOVDconst [c])) && is32Bit(c) => (ADDconst [int32(c)] x)
+(ADD x (MOVDconst <t> [c])) && is32Bit(c) && !t.IsPtr() => (ADDconst [int32(c)] x)
 (ADDW x (MOVDconst [c])) => (ADDWconst [int32(c)] x)
 
 (SUB x (MOVDconst [c])) && is32Bit(c) => (SUBconst x [int32(c)])

diff --git a/src/cmd/compile/internal/ssa/_gen/Wasm.rules b/src/cmd/compile/internal/ssa/_gen/Wasm.rules
@@ -372,7 +372,7 @@
 (I64LeU (I64Const [1]) x) => (I64Eqz (I64Eqz x))
 (I64Ne x (I64Const [0])) => (I64Eqz (I64Eqz x))
 
-(I64Add x (I64Const [y])) => (I64AddConst [y] x)
+(I64Add x (I64Const <t> [y])) && !t.IsPtr() => (I64AddConst [y] x)
 (I64AddConst [0] x) => x
 (I64Eqz (I64Eqz (I64Eqz x))) => (I64Eqz x)
 

diff --git a/src/cmd/compile/internal/ssa/rewrite386.go b/src/cmd/compile/internal/ssa/rewrite386.go
diff --git a/src/cmd/compile/internal/ssa/rewriteAMD64.go b/src/cmd/compile/internal/ssa/rewriteAMD64.go
diff --git a/src/cmd/compile/internal/ssa/rewriteARM.go b/src/cmd/compile/internal/ssa/rewriteARM.go
diff --git a/src/cmd/compile/internal/ssa/rewriteARM64.go b/src/cmd/compile/internal/ssa/rewriteARM64.go
diff --git a/src/cmd/compile/internal/ssa/rewriteLOONG64.go b/src/cmd/compile/internal/ssa/rewriteLOONG64.go
diff --git a/src/cmd/compile/internal/ssa/rewriteMIPS.go b/src/cmd/compile/internal/ssa/rewriteMIPS.go
diff --git a/src/cmd/compile/internal/ssa/rewriteMIPS64.go b/src/cmd/compile/internal/ssa/rewriteMIPS64.go
diff --git a/src/cmd/compile/internal/ssa/rewritePPC64.go b/src/cmd/compile/internal/ssa/rewritePPC64.go
diff --git a/src/cmd/compile/internal/ssa/rewriteRISCV64.go b/src/cmd/compile/internal/ssa/rewriteRISCV64.go
diff --git a/src/cmd/compile/internal/ssa/rewriteS390X.go b/src/cmd/compile/internal/ssa/rewriteS390X.go
diff --git a/src/cmd/compile/internal/ssa/rewriteWasm.go b/src/cmd/compile/internal/ssa/rewriteWasm.go