e2d7cd685d
This patch makes the dead_on_return parameter attribute optionally require a number
of bytes to be passed in to specify the number of bytes known to be dead
upon function return/unwind. This is aimed at enabling annotating the
this pointer in C++ destructors with dead_on_return in clang. We need
this to handle cases like the following:
```
struct X {
int n;
~X() {
this[n].n = 0;
}
};
void f() {
X xs[] = {42, -1};
}
```
Where we only certain that sizeof(X) bytes are dead upon return of ~X.
Otherwise DSE would be able to eliminate the store in ~X which would not
be correct.
This patch only does the wiring within IR. Future patches will make
clang emit correct sizing information and update DSE to only delete
stores to objects marked dead_on_return that are provably in bounds of
the number of bytes specified to be dead_on_return.
Reviewers: nikic, alinas, antoniofrighetto
Pull Request: https://github.com/llvm/llvm-project/pull/171712
101 lines
8.0 KiB
C
101 lines
8.0 KiB
C
// RUN: %clang_cc1 -emit-llvm %s -o - -ffreestanding -triple=i386-pc-win32 | FileCheck %s --check-prefixes=X86,Win32
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// RUN: %clang_cc1 -emit-llvm %s -o - -ffreestanding -triple=x86_64-pc-win32 | FileCheck %s --check-prefixes=X64,Win64
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// RUN: %clang_cc1 -emit-llvm %s -o - -ffreestanding -triple=i386-pc-linux-gnu | FileCheck %s --check-prefixes=X86,Lin32
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// RUN: %clang_cc1 -emit-llvm %s -o - -ffreestanding -triple=x86_64-pc-linux-gnu | FileCheck %s --check-prefixes=X64,Lin64
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#include <xmmintrin.h>
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void __regcall v1(int a, int b) {}
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// X86: define dso_local x86_regcallcc void @__regcall3__v1(i32 inreg noundef %a, i32 inreg noundef %b)
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// X64: define dso_local x86_regcallcc void @__regcall3__v1(i32 noundef %a, i32 noundef %b)
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void __attribute__((regcall)) v1b(int a, int b) {}
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// X86: define dso_local x86_regcallcc void @__regcall3__v1b(i32 inreg noundef %a, i32 inreg noundef %b)
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// X64: define dso_local x86_regcallcc void @__regcall3__v1b(i32 noundef %a, i32 noundef %b)
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void __regcall v2(char a, char b) {}
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// X86: define dso_local x86_regcallcc void @__regcall3__v2(i8 inreg noundef signext %a, i8 inreg noundef signext %b)
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// Win64: define dso_local x86_regcallcc void @__regcall3__v2(i8 noundef %a, i8 noundef %b)
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// Lin64: define dso_local x86_regcallcc void @__regcall3__v2(i8 noundef signext %a, i8 noundef signext %b)
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struct Small { int x; };
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void __regcall v3(int a, struct Small b, int c) {}
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// Win32: define dso_local x86_regcallcc void @__regcall3__v3(i32 inreg noundef %a, i32 %b.0, i32 inreg noundef %c)
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// Lin32: define dso_local x86_regcallcc void @__regcall3__v3(i32 inreg noundef %a, i32 inreg %0, i32 %b.0, i32 inreg noundef %c)
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// X64: define dso_local x86_regcallcc void @__regcall3__v3(i32 noundef %a, i32 %b.coerce, i32 noundef %c)
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struct Large { int a[5]; };
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void __regcall v4(int a, struct Large b, int c) {}
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// Win32: define dso_local x86_regcallcc void @__regcall3__v4(i32 inreg noundef %a, ptr noundef byval(%struct.Large) align 4 %b, i32 inreg noundef %c)
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// Lin32: define dso_local x86_regcallcc void @__regcall3__v4(i32 inreg noundef %a, ptr noundef byval(%struct.Large) align 4 %b, i32 noundef %c)
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// Win64: define dso_local x86_regcallcc void @__regcall3__v4(i32 noundef %a, ptr noundef dead_on_return %b, i32 noundef %c)
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// Lin64: define dso_local x86_regcallcc void @__regcall3__v4(i32 noundef %a, [5 x i32] %b.coerce, i32 noundef %c)
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void __regcall v5(long long a, int b, int c) {}
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// X86: define dso_local x86_regcallcc void @__regcall3__v5(i64 noundef %a, i32 inreg noundef %b, i32 inreg noundef %c)
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// X64: define dso_local x86_regcallcc void @__regcall3__v5(i64 noundef %a, i32 noundef %b, i32 noundef %c)
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struct HFA2 { double x, y; };
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struct HFA4 { double w, x, y, z; };
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struct HFA5 { double v, w, x, y, z; };
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void __regcall hfa1(int a, struct HFA4 b, int c) {}
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// X86: define dso_local x86_regcallcc void @__regcall3__hfa1(i32 inreg noundef %a, double %b.0, double %b.1, double %b.2, double %b.3, i32 inreg noundef %c)
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// X64: define dso_local x86_regcallcc void @__regcall3__hfa1(i32 noundef %a, double %{{.*}}, double %{{.*}}, double %{{.*}}, double %{{.*}}, i32 noundef %c)
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// HFAs that would require more than six total SSE registers are passed
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// indirectly. Additional vector arguments can consume the rest of the SSE
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// registers.
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void __regcall hfa2(struct HFA4 a, struct HFA4 b, double c) {}
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// X86: define dso_local x86_regcallcc void @__regcall3__hfa2(double %a.0, double %a.1, double %a.2, double %a.3, double %b.0, double %b.1, double %b.2, double %b.3, ptr inreg noundef dead_on_return %0)
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// X64: define dso_local x86_regcallcc void @__regcall3__hfa2(double %{{.*}}, double %{{.*}}, double %{{.*}}, double %{{.*}}, double %{{.*}}, double %{{.*}}, double %{{.*}}, double %{{.*}}, double noundef %c)
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// Ensure that we pass builtin types directly while counting them against the
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// SSE register usage.
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void __regcall hfa3(double a, double b, double c, double d, double e, struct HFA2 f) {}
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// X86: define dso_local x86_regcallcc void @__regcall3__hfa3(double noundef %a, double noundef %b, double noundef %c, double noundef %d, double noundef %e, double %f.0, double %f.1)
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// X64: define dso_local x86_regcallcc void @__regcall3__hfa3(double noundef %a, double noundef %b, double noundef %c, double noundef %d, double noundef %e, double %{{.*}}, double %{{.*}})
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// Aggregates with more than four elements are not HFAs and are passed byval(%b.3, double noundef).
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// Because they are not classified as homogeneous, they don't get special
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// handling to ensure alignment.
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void __regcall hfa4(struct HFA5 a) {}
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// X32: define dso_local x86_regcallcc void @__regcall3__hfa4(ptr noundef byval(%struct.HFA5) align 4 %{{.*}})
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// Win64: define dso_local x86_regcallcc void @__regcall3__hfa4(ptr noundef dead_on_return %a)
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// Lin64: define dso_local x86_regcallcc void @__regcall3__hfa4(double %a.coerce0, double %a.coerce1, double %a.coerce2, double %a.coerce3, double %a.coerce4)
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// Return HFAs of 4 or fewer elements in registers.
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static struct HFA2 g_hfa2;
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struct HFA2 __regcall hfa5(void) { return g_hfa2; }
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// X86: define dso_local x86_regcallcc %struct.HFA2 @__regcall3__hfa5()
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// X64: define dso_local x86_regcallcc %struct.HFA2 @__regcall3__hfa5()
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typedef float __attribute__((vector_size(16))) v4f32;
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struct HVA2 { v4f32 x, y; };
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struct HVA4 { v4f32 w, x, y, z; };
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void __regcall hva1(int a, struct HVA4 b, int c) {}
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// X86: define dso_local x86_regcallcc void @__regcall3__hva1(i32 inreg noundef %a, <4 x float> %b.0, <4 x float> %b.1, <4 x float> %b.2, <4 x float> %b.3, i32 inreg noundef %c)
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// X64: define dso_local x86_regcallcc void @__regcall3__hva1(i32 noundef %a, <4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}}, i32 noundef %c)
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void __regcall hva2(struct HVA4 a, struct HVA4 b, v4f32 c) {}
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// X86: define dso_local x86_regcallcc void @__regcall3__hva2(<4 x float> %a.0, <4 x float> %a.1, <4 x float> %a.2, <4 x float> %a.3, <4 x float> %b.0, <4 x float> %b.1, <4 x float> %b.2, <4 x float> %b.3, ptr inreg noundef dead_on_return %0)
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// X64: define dso_local x86_regcallcc void @__regcall3__hva2(<4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> %{{.*}}, <4 x float> noundef %c)
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void __regcall hva3(v4f32 a, v4f32 b, v4f32 c, v4f32 d, v4f32 e, struct HVA2 f) {}
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// X86: define dso_local x86_regcallcc void @__regcall3__hva3(<4 x float> noundef %a, <4 x float> noundef %b, <4 x float> noundef %c, <4 x float> noundef %d, <4 x float> noundef %e, <4 x float> %f.0, <4 x float> %f.1)
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// X64: define dso_local x86_regcallcc void @__regcall3__hva3(<4 x float> noundef %a, <4 x float> noundef %b, <4 x float> noundef %c, <4 x float> noundef %d, <4 x float> noundef %e, <4 x float> %{{.*}}, <4 x float> %{{.*}})
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typedef float __attribute__((ext_vector_type(3))) v3f32;
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struct OddSizeHVA { v3f32 x, y; };
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void __regcall odd_size_hva(struct OddSizeHVA a) {}
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// X86: define dso_local x86_regcallcc void @__regcall3__odd_size_hva(<3 x float> %a.0, <3 x float> %a.1)
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// X64: define dso_local x86_regcallcc void @__regcall3__odd_size_hva(<3 x float> %{{.*}}, <3 x float> %{{.*}})
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struct HFA6 { __m128 f[4]; };
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struct HFA6 __regcall ret_reg_reused(struct HFA6 a, struct HFA6 b, struct HFA6 c, struct HFA6 d){ struct HFA6 h; return h;}
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// X86: define dso_local x86_regcallcc %struct.HFA6 @__regcall3__ret_reg_reused(<4 x float> %a.0, <4 x float> %a.1, <4 x float> %a.2, <4 x float> %a.3, <4 x float> %b.0, <4 x float> %b.1, <4 x float> %b.2, <4 x float> %b.3, ptr inreg noundef dead_on_return %c, ptr inreg noundef dead_on_return %d)
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// Win64: define dso_local x86_regcallcc %struct.HFA6 @__regcall3__ret_reg_reused(<4 x float> %a.0, <4 x float> %a.1, <4 x float> %a.2, <4 x float> %a.3, <4 x float> %b.0, <4 x float> %b.1, <4 x float> %b.2, <4 x float> %b.3, <4 x float> %c.0, <4 x float> %c.1, <4 x float> %c.2, <4 x float> %c.3, <4 x float> %d.0, <4 x float> %d.1, <4 x float> %d.2, <4 x float> %d.3)
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// Lin64: define dso_local x86_regcallcc %struct.HFA6 @__regcall3__ret_reg_reused([4 x <4 x float>] %a.coerce, [4 x <4 x float>] %b.coerce, [4 x <4 x float>] %c.coerce, [4 x <4 x float>] %d.coerce)
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