[llvm] r241002 - X86: Rework inline asm integer register specification.
Matthias Braun
matze at braunis.de
Mon Jun 29 14:35:52 PDT 2015
Author: matze
Date: Mon Jun 29 16:35:51 2015
New Revision: 241002
URL: http://llvm.org/viewvc/llvm-project?rev=241002&view=rev
Log:
X86: Rework inline asm integer register specification.
This is a new version of http://reviews.llvm.org/D10260.
It turned out that when you specify an integer register in inline asm on
x86 you get the register of the required type size back. That means that
X86TargetLowering::getRegForInlineAsmConstraint() has to accept any of
the integer registers and adapt its size to the given target size which
may be any 8/16/32/64 bit sized type. Surprisingly that means given a
constraint of "{ax}" and a type of MVT::F32 we need to return X86::EAX.
This change makes this face explicit, the previous code seemed like
working by accident because there it never returned an error once a
register was found. On the other hand this rewrite allows to actually
return errors for invalid situations like requesting an integer register
for an i128 type.
Related to rdar://21042280
Differential Revision: http://reviews.llvm.org/D10813
Added:
llvm/trunk/test/CodeGen/X86/asm-mismatched-types.ll
llvm/trunk/test/CodeGen/X86/asm-reject-reg-type-mismatch.ll
Modified:
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
llvm/trunk/lib/Target/X86/X86RegisterInfo.cpp
llvm/trunk/lib/Target/X86/X86RegisterInfo.h
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=241002&r1=241001&r2=241002&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Mon Jun 29 16:35:51 2015
@@ -25580,71 +25580,40 @@ X86TargetLowering::getRegForInlineAsmCon
// Otherwise, check to see if this is a register class of the wrong value
// type. For example, we want to map "{ax},i32" -> {eax}, we don't want it to
// turn into {ax},{dx}.
- if (Res.second->hasType(VT))
+ // MVT::Other is used to specify clobber names.
+ if (Res.second->hasType(VT) || VT == MVT::Other)
return Res; // Correct type already, nothing to do.
- // All of the single-register GCC register classes map their values onto
- // 16-bit register pieces "ax","dx","cx","bx","si","di","bp","sp". If we
- // really want an 8-bit or 32-bit register, map to the appropriate register
- // class and return the appropriate register.
- if (Res.second == &X86::GR16RegClass) {
- if (VT == MVT::i8 || VT == MVT::i1) {
- unsigned DestReg = 0;
- switch (Res.first) {
- default: break;
- case X86::AX: DestReg = X86::AL; break;
- case X86::DX: DestReg = X86::DL; break;
- case X86::CX: DestReg = X86::CL; break;
- case X86::BX: DestReg = X86::BL; break;
- }
- if (DestReg) {
- Res.first = DestReg;
- Res.second = &X86::GR8RegClass;
- }
- } else if (VT == MVT::i32 || VT == MVT::f32) {
- unsigned DestReg = 0;
- switch (Res.first) {
- default: break;
- case X86::AX: DestReg = X86::EAX; break;
- case X86::DX: DestReg = X86::EDX; break;
- case X86::CX: DestReg = X86::ECX; break;
- case X86::BX: DestReg = X86::EBX; break;
- case X86::SI: DestReg = X86::ESI; break;
- case X86::DI: DestReg = X86::EDI; break;
- case X86::BP: DestReg = X86::EBP; break;
- case X86::SP: DestReg = X86::ESP; break;
- }
- if (DestReg) {
- Res.first = DestReg;
- Res.second = &X86::GR32RegClass;
- }
- } else if (VT == MVT::i64 || VT == MVT::f64) {
- unsigned DestReg = 0;
- switch (Res.first) {
- default: break;
- case X86::AX: DestReg = X86::RAX; break;
- case X86::DX: DestReg = X86::RDX; break;
- case X86::CX: DestReg = X86::RCX; break;
- case X86::BX: DestReg = X86::RBX; break;
- case X86::SI: DestReg = X86::RSI; break;
- case X86::DI: DestReg = X86::RDI; break;
- case X86::BP: DestReg = X86::RBP; break;
- case X86::SP: DestReg = X86::RSP; break;
- }
- if (DestReg) {
- Res.first = DestReg;
- Res.second = &X86::GR64RegClass;
- }
+ // Get a matching integer of the correct size. i.e. "ax" with MVT::32 should
+ // return "eax". This should even work for things like getting 64bit integer
+ // registers when given an f64 type.
+ const TargetRegisterClass *Class = Res.second;
+ if (Class == &X86::GR8RegClass || Class == &X86::GR16RegClass ||
+ Class == &X86::GR32RegClass || Class == &X86::GR64RegClass) {
+ unsigned Size = VT.getSizeInBits();
+ MVT::SimpleValueType SimpleTy = Size == 1 || Size == 8 ? MVT::i8
+ : Size == 16 ? MVT::i16
+ : Size == 32 ? MVT::i32
+ : Size == 64 ? MVT::i64
+ : MVT::Other;
+ unsigned DestReg = getX86SubSuperRegisterOrZero(Res.first, SimpleTy);
+ if (DestReg > 0) {
+ Res.first = DestReg;
+ Res.second = SimpleTy == MVT::i8 ? &X86::GR8RegClass
+ : SimpleTy == MVT::i16 ? &X86::GR16RegClass
+ : SimpleTy == MVT::i32 ? &X86::GR32RegClass
+ : &X86::GR64RegClass;
+ assert(Res.second->contains(Res.first) && "Register in register class");
+ } else {
+ // No register found/type mismatch.
+ Res.first = 0;
+ Res.second = nullptr;
}
- } else if (Res.second == &X86::FR32RegClass ||
- Res.second == &X86::FR64RegClass ||
- Res.second == &X86::VR128RegClass ||
- Res.second == &X86::VR256RegClass ||
- Res.second == &X86::FR32XRegClass ||
- Res.second == &X86::FR64XRegClass ||
- Res.second == &X86::VR128XRegClass ||
- Res.second == &X86::VR256XRegClass ||
- Res.second == &X86::VR512RegClass) {
+ } else if (Class == &X86::FR32RegClass || Class == &X86::FR64RegClass ||
+ Class == &X86::VR128RegClass || Class == &X86::VR256RegClass ||
+ Class == &X86::FR32XRegClass || Class == &X86::FR64XRegClass ||
+ Class == &X86::VR128XRegClass || Class == &X86::VR256XRegClass ||
+ Class == &X86::VR512RegClass) {
// Handle references to XMM physical registers that got mapped into the
// wrong class. This can happen with constraints like {xmm0} where the
// target independent register mapper will just pick the first match it can
@@ -25660,6 +25629,11 @@ X86TargetLowering::getRegForInlineAsmCon
Res.second = &X86::VR256RegClass;
else if (X86::VR512RegClass.hasType(VT))
Res.second = &X86::VR512RegClass;
+ else {
+ // Type mismatch and not a clobber: Return an error;
+ Res.first = 0;
+ Res.second = nullptr;
+ }
}
return Res;
Modified: llvm/trunk/lib/Target/X86/X86RegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86RegisterInfo.cpp?rev=241002&r1=241001&r2=241002&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86RegisterInfo.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86RegisterInfo.cpp Mon Jun 29 16:35:51 2015
@@ -598,10 +598,10 @@ X86RegisterInfo::getPtrSizedFrameRegiste
}
namespace llvm {
-unsigned getX86SubSuperRegister(unsigned Reg, MVT::SimpleValueType VT,
- bool High) {
+unsigned getX86SubSuperRegisterOrZero(unsigned Reg, MVT::SimpleValueType VT,
+ bool High) {
switch (VT) {
- default: llvm_unreachable("Unexpected VT");
+ default: return 0;
case MVT::i8:
if (High) {
switch (Reg) {
@@ -625,7 +625,7 @@ unsigned getX86SubSuperRegister(unsigned
}
} else {
switch (Reg) {
- default: llvm_unreachable("Unexpected register");
+ default: return 0;
case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
return X86::AL;
case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
@@ -662,7 +662,7 @@ unsigned getX86SubSuperRegister(unsigned
}
case MVT::i16:
switch (Reg) {
- default: llvm_unreachable("Unexpected register");
+ default: return 0;
case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
return X86::AX;
case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
@@ -698,7 +698,7 @@ unsigned getX86SubSuperRegister(unsigned
}
case MVT::i32:
switch (Reg) {
- default: llvm_unreachable("Unexpected register");
+ default: return 0;
case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
return X86::EAX;
case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
@@ -734,7 +734,7 @@ unsigned getX86SubSuperRegister(unsigned
}
case MVT::i64:
switch (Reg) {
- default: llvm_unreachable("Unexpected register");
+ default: return 0;
case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
return X86::RAX;
case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
@@ -771,6 +771,14 @@ unsigned getX86SubSuperRegister(unsigned
}
}
+unsigned getX86SubSuperRegister(unsigned Reg, MVT::SimpleValueType VT,
+ bool High) {
+ unsigned Res = getX86SubSuperRegisterOrZero(Reg, VT, High);
+ if (Res == 0)
+ llvm_unreachable("Unexpected register or VT");
+ return Res;
+}
+
unsigned get512BitSuperRegister(unsigned Reg) {
if (Reg >= X86::XMM0 && Reg <= X86::XMM31)
return X86::ZMM0 + (Reg - X86::XMM0);
Modified: llvm/trunk/lib/Target/X86/X86RegisterInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86RegisterInfo.h?rev=241002&r1=241001&r2=241002&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86RegisterInfo.h (original)
+++ llvm/trunk/lib/Target/X86/X86RegisterInfo.h Mon Jun 29 16:35:51 2015
@@ -128,11 +128,16 @@ public:
unsigned getSlotSize() const { return SlotSize; }
};
-// getX86SubSuperRegister - X86 utility function. It returns the sub or super
-// register of a specific X86 register.
-// e.g. getX86SubSuperRegister(X86::EAX, MVT::i16) return X86:AX
+/// Returns the sub or super register of a specific X86 register.
+/// e.g. getX86SubSuperRegister(X86::EAX, MVT::i16) returns X86::AX.
+/// Aborts on error.
unsigned getX86SubSuperRegister(unsigned, MVT::SimpleValueType, bool High=false);
+/// Returns the sub or super register of a specific X86 register.
+/// Like getX86SubSuperRegister() but returns 0 on error.
+unsigned getX86SubSuperRegisterOrZero(unsigned, MVT::SimpleValueType,
+ bool High = false);
+
//get512BitRegister - X86 utility - returns 512-bit super register
unsigned get512BitSuperRegister(unsigned Reg);
Added: llvm/trunk/test/CodeGen/X86/asm-mismatched-types.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/asm-mismatched-types.ll?rev=241002&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/asm-mismatched-types.ll (added)
+++ llvm/trunk/test/CodeGen/X86/asm-mismatched-types.ll Mon Jun 29 16:35:51 2015
@@ -0,0 +1,135 @@
+; RUN: llc -o - %s -no-integrated-as | FileCheck %s
+target triple = "x86_64--"
+
+; Allow to specify any of the 8/16/32/64 register names interchangeably in
+; constraints
+
+; Produced by C-programs like this:
+; void foo(int p) { register int reg __asm__("r8") = p;
+; __asm__ __volatile__("# REG: %0" : : "r" (reg)); }
+
+; CHECK-LABEL: reg64_as_32:
+; CHECK: # REG: %r8d
+define void @reg64_as_32(i32 %p) {
+ call void asm sideeffect "# REG: $0", "{r8}"(i32 %p)
+ ret void
+}
+
+; CHECK-LABEL: reg64_as_32_float:
+; CHECK: # REG: %r8d
+define void @reg64_as_32_float(float %p) {
+ call void asm sideeffect "# REG: $0", "{r8}"(float %p)
+ ret void
+}
+
+; CHECK-LABEL: reg64_as_16:
+; CHECK: # REG: %r9w
+define void @reg64_as_16(i16 %p) {
+ call void asm sideeffect "# REG: $0", "{r9}"(i16 %p)
+ ret void
+}
+
+; CHECK-LABEL: reg64_as_8:
+; CHECK: # REG: %bpl
+define void @reg64_as_8(i8 %p) {
+ call void asm sideeffect "# REG: $0", "{rbp}"(i8 %p)
+ ret void
+}
+
+; CHECK-LABEL: reg32_as_16:
+; CHECK: # REG: %r15w
+define void @reg32_as_16(i16 %p) {
+ call void asm sideeffect "# REG: $0", "{r15d}"(i16 %p)
+ ret void
+}
+
+; CHECK-LABEL: reg32_as_8:
+; CHECK: # REG: %r12b
+define void @reg32_as_8(i8 %p) {
+ call void asm sideeffect "# REG: $0", "{r12d}"(i8 %p)
+ ret void
+}
+
+; CHECK-LABEL: reg16_as_8:
+; CHECK: # REG: %cl
+define void @reg16_as_8(i8 %p) {
+ call void asm sideeffect "# REG: $0", "{cx}"(i8 %p)
+ ret void
+}
+
+; CHECK-LABEL: reg32_as_64:
+; CHECK: # REG: %rbp
+define void @reg32_as_64(i64 %p) {
+ call void asm sideeffect "# REG: $0", "{ebp}"(i64 %p)
+ ret void
+}
+
+; CHECK-LABEL: reg32_as_64_float:
+; CHECK: # REG: %rbp
+define void @reg32_as_64_float(double %p) {
+ call void asm sideeffect "# REG: $0", "{ebp}"(double %p)
+ ret void
+}
+
+; CHECK-LABEL: reg16_as_64:
+; CHECK: # REG: %r13
+define void @reg16_as_64(i64 %p) {
+ call void asm sideeffect "# REG: $0", "{r13w}"(i64 %p)
+ ret void
+}
+
+; CHECK-LABEL: reg16_as_64_float:
+; CHECK: # REG: %r13
+define void @reg16_as_64_float(double %p) {
+ call void asm sideeffect "# REG: $0", "{r13w}"(double %p)
+ ret void
+}
+
+; CHECK-LABEL: reg8_as_64:
+; CHECK: # REG: %rax
+define void @reg8_as_64(i64 %p) {
+ call void asm sideeffect "# REG: $0", "{al}"(i64 %p)
+ ret void
+}
+
+; CHECK-LABEL: reg8_as_64_float:
+; CHECK: # REG: %rax
+define void @reg8_as_64_float(double %p) {
+ call void asm sideeffect "# REG: $0", "{al}"(double %p)
+ ret void
+}
+
+; CHECK-LABEL: reg16_as_32:
+; CHECK: # REG: %r11d
+define void @reg16_as_32(i32 %p) {
+ call void asm sideeffect "# REG: $0", "{r11w}"(i32 %p)
+ ret void
+}
+
+; CHECK-LABEL: reg16_as_32_float:
+; CHECK: # REG: %r11d
+define void @reg16_as_32_float(float %p) {
+ call void asm sideeffect "# REG: $0", "{r11w}"(float %p)
+ ret void
+}
+
+; CHECK-LABEL: reg8_as_32:
+; CHECK: # REG: %r9d
+define void @reg8_as_32(i32 %p) {
+ call void asm sideeffect "# REG: $0", "{r9b}"(i32 %p)
+ ret void
+}
+
+; CHECK-LABEL: reg8_as_32_float:
+; CHECK: # REG: %r9d
+define void @reg8_as_32_float(float %p) {
+ call void asm sideeffect "# REG: $0", "{r9b}"(float %p)
+ ret void
+}
+
+; CHECK-LABEL: reg8_as_16:
+; CHECK: # REG: %di
+define void @reg8_as_16(i16 %p) {
+ call void asm sideeffect "# REG: $0", "{dil}"(i16 %p)
+ ret void
+}
Added: llvm/trunk/test/CodeGen/X86/asm-reject-reg-type-mismatch.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/asm-reject-reg-type-mismatch.ll?rev=241002&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/asm-reject-reg-type-mismatch.ll (added)
+++ llvm/trunk/test/CodeGen/X86/asm-reject-reg-type-mismatch.ll Mon Jun 29 16:35:51 2015
@@ -0,0 +1,8 @@
+; RUN: not llc -o /dev/null %s 2>&1 | FileCheck %s
+target triple = "x86_64--"
+
+; CHECK: error: couldn't allocate output register for constraint '{ax}'
+define i128 @blup() {
+ %v = tail call i128 asm "", "={ax},0"(i128 0)
+ ret i128 %v
+}
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